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319 results on '"Fersch R"'

1. Measurement of charged-pion production in deep-inelastic scattering off nuclei with the CLAS detector

Author: Moran, S., Dupre, R., Hakobyan, H., Arratia, M., Brooks, W. K., Borquez, A., Alaoui, A. El, Fassi, L. El, Hafidi, K., Mendez, R., Mineeva, T., Paul, S. J., Amaryan, M. J., Angelini, Giovanni, Armstrong, Whitney R., Atac, H., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biondo, L., Biselli, A. S., Bossu, F., Boiarinov, S., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Egiyan, H., Elouadrhiri, L., Eugenio, P., Fersch, R., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Golubenko, A. A., Gothe, R. W., Griffioen, K. A., Guidal, M., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Keller, D., Khanal, A., Khandaker, M., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J . D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Ostrovidov, A. I., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, Trevor, Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, Kevin, Wei, X., Weinstein, L. B., Wishart, R., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Background: Energetic quarks in nuclear DIS propagate through the nuclear medium. Processes that are believed to occur inside nuclei include quark energy loss through medium-stimulated gluon bremsstrahlung and intra-nuclear interactions of forming hadrons. More data are required to gain a more complete understanding of these effects. Purpose: To test the theoretical models of parton transport and hadron formation, we compared their predictions for the nuclear and kinematic dependence of pion production in nuclei. Methods: We have measured charged-pion production in semi-inclusive DIS off D, C, Fe, and Pb using the CLAS detector and the CEBAF 5.014 GeV electron beam. We report results on the nuclear-to-deuterium multiplicity ratio for $\pi^{+}$ and $\pi^{-}$ as a function of energy transfer, four-momentum transfer, and pion energy fraction or transverse momentum - the first three-dimensional study of its kind. Results: The $\pi^{+}$ multiplicity ratio is found to depend strongly on the pion fractional energy $z$, and reaches minimum values of $0.67\pm0.03$, $0.43\pm0.02$, and $0.27\pm0.01$ for the C, Fe, and Pb targets, respectively. The $z$ dependences of the multiplicity ratios for $\pi^{+}$ and $\pi^{-}$ are equal within uncertainties for C and Fe targets but show differences at the level of 10$\%$ for the Pb-target data. The results are qualitatively described by the GiBUU transport model, as well as with a model based on hadron absorption, but are in tension with calculations based on nuclear fragmentation functions. Conclusions: These precise results will strongly constrain the kinematic and flavor dependence of nuclear effects in hadron production, probing an unexplored kinematic region. They will help to reveal how the nucleus reacts to a fast quark, thereby shedding light on its color structure, transport properties, and on the mechanisms of the hadronization process., Comment: 22 pages, 5 figures, 12 tables
Published: 2021
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2. First-time measurement of Timelike Compton Scattering

Author: Chatagnon, P., Niccolai, S., Stepanyan, S., Amaryan, M. J., Angelini, G., Armstrong, W. R., Atac, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Caudron, M., Celentano, A., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., Defurne, M., De Vita, R., Deur, A., Diehl, S., Djalali, C., Dupré, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Fersch, R., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Kabir, M. L., Keller, D., Khachatryan, G., Khanal, A., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., MacGregor, I . J . D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Migliorati, S., Mirazita, M., Mokeev, V., Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., O'Connell, T. R., Osipenko, M., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Ripani, M., Rizzo, A., Rossi, P., Rowley, J., Sabatié, F., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyler, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wishart, R., Yale, B., Zachariou, N., Zhang, J., Zhao, Z. W., and Collaboration, the CLAS
Subjects: High Energy Physics - Experiment
Abstract: We present the first measurement of the Timelike Compton Scattering process, $\gamma p\to p^\prime \gamma^* (\gamma^*\to e^+e^-) $, obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities $2.25
Published: 2021
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3. Improved $\Lambda p$ Elastic Scattering Cross Sections Between 0.9 and 2.0 GeV/c and Connections to the Neutron Star Equation of State

Author: CLAS Collaboration, Rowley, J., Compton, N., Djalali, C., Hicks, K., Price, J., Zachariou, N., Adhikari, K. P., Armstrong, W. R., Atac, H., Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Gavalian, G., Girod, F. X., Glazier, D. I., Golubenko, A., Gothe, R. W., Griffioen, K., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, A., Korover, I., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McCracken, M. E., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Pogorelko, O., Prok, Y., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D., Wei, K., Wei, X., Wishart, R., Wood, M. H., Yale, B., Yurov, M., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state (EOS). Yet, compared to other elastic scattering processes, there is very little data on $\Lambda$-$N$ scattering. This experiment utilized the CLAS detector to study the $\Lambda p \rightarrow \Lambda p$ elastic scattering cross section in the incident $\Lambda$ momentum range 0.9-2.0 GeV/c. This is the first data on this reaction in several decades. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments., Comment: 6 pages, 5 figures
Published: 2021

4. Measurement of the proton spin structure at long distances

Author: Zheng, X., Deur, A., Kang, H., Kuhn, S. E., Ripani, M., Zhang, J., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Atac, H., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boiarinov, S., Bondi, M., Bossu, F., Bosted, P., Briscoe, W. J., Brock, J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carlin, C., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Chen, J. -P., Choi, S., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Drozdov, V. A., Dupre, R., Ehrhart, M., Alaoui, A. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Forest, T. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. -X., Glazier, D. I., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holmstrom, T., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keith, C. D., Keller, D., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., livingston, K., Long, E., MacGregor, I. J. D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meekins, D. G., Mineeva, T., Mirazita, M., Mokeev, V., Mullen, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L., Park, K., Pasyuk, E., Phelps, W., Phillips, S. K., Pogorelko, O., Poudel, J., Prok, Y., Raue, B. A., Ritman, J., Rizzo, A., Rosner, G., Rossi, P., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Seely, M. L., Sharabian, Y. G., Shrestha, U., Sirca, S., Slifer, K., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sulkosky, V., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Yale, B., Zachariou, N., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Measuring the spin structure of protons and neutrons tests our understanding of how they arise from quarks and gluons, the fundamental building blocks of nuclear matter. At long distances the coupling constant of the strong interaction becomes large, requiring non-perturbative methods to calculate quantum chromodynamics processes, such as lattice gauge theory or effective field theories. Here we report proton spin structure measurements from scattering a polarized electron beam off polarized protons. The spin-dependent cross-sections were measured at large distances, corresponding to the region of low momentum transfer squared between 0.012 and 1.0 GeV$^2$. This kinematic range provides unique tests of chiral effective field theory predictions. Our results show that a complete description of the nucleon spin remains elusive, and call for further theoretical works, e.g. in lattice quantum chromodynamics. Finally, our data extrapolated to the photon point agree with the Gerasimov-Drell-Hearn sum rule, a fundamental prediction of quantum field theory that relates the anomalous magnetic moment of the proton to its integrated spin-dependent cross-sections., Comment: Published version. 10 pages, 5 figures. 20 pages of supplementary material (data tables and a figure)
Published: 2021
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5. Beam spin asymmetry in semi-inclusive electroproduction of a hadron pair

Author: Mirazita, M., Avakian, H., Courtoy, A., Pisano, S., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biselli, A. S., Bossu', F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fegan, S., Fersch, R., Filippi, A., Forest, T. A., Ghandilyan, Y., Gavalian, G., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Huang, Q., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I . J . D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Milner, R. G., Mineeva, T., Mokeev, V., Mullen, C., Camacho, C. Munoz, Neupane, K., Niculescu, G., O'Connell, T., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pocanic, D., Pogorelko, O., Poudel, J., Prok, Y., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Sabatie', F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: A first measurement of the longitudinal beam spin asymmetry ALU in the semi-inclusive electroproduction of pairs of charged pions is reported. ALU is a higher-twist observable and offers the cleanest access to the nucleon twist-3 parton distribution function e(x). Data have been collected in the Hall-B at Jefferson Lab by impinging a 5.498 GeV electron beam on a liquid-hydrogen target, and reconstructing the scattered electron and the pion pair with the CLAS detector. One-dimensional projections of the sin(phiR) moments of ALU are extracted for the kinematic variables of interest in the valence quark region. The understanding of di-hadron production is essential for the interpretation of observables in single hadron production in semi-inclusive DIS, and pioneering measurements of single spin asymmetries in di-hadron production open a new avenue in studies of QCD dynamics.
Published: 2020
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6. Photoproduction of $\eta$ mesons off the proton for $1.2 < E_\gamma < 4.7$ GeV using CLAS at Jefferson Laboratory

Author: Hu, T., Akbar, Z., Crede, V., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Asryan, G., Atac, H., Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Carman, D. S., Carvajal, J., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Cruz-Torres, R., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Illari, I., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Mascagna, V., McCracken, M. E., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to \pi^+\pi^-\pi^0$, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new $\eta$ photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are also compared with the experimental results from several other experiments, and with predictions of $\eta$ MAID\,2018 and the latest solution of the Bonn-Gatchina coupled-channel analysis. Differential cross sections $d\sigma/dt$ are presented for incident photon energies $E_\gamma > 2.9$ GeV ($W > 2.5$ GeV), and compared with predictions which are based on Regge trajectories exchange in the $t$-channel (Regge models). The data confirm the expected dominance of $\rho$, $\omega$ vector-meson exchange in an analysis by the Joint Physics Analysis Center., Comment: 24 pages, 22 figures
Published: 2020
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7. First results on nucleon resonance photocouplings from the $\gamma p \to \pi^+\pi^-p$ reaction

Author: CLAS Collaboration, Golovatch, E., Burkert, V. D., Carman, D. S., Gothe, R. W., Hicks, K., Ishkhanov, B. S., Mokeev, V. I., Pasyuk, E., Adhikari, S., Akbar, Z., Amaryan, M. J., Avakian, H., Ball, J., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Cao, F., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joo, K., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., McKinnon, B., Meyer, C. A., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment
Abstract: We report the first experimental measurements of the nine 1-fold differential cross sections for the $\gamma p \to \pi^+\pi^-p$ reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6~GeV~$
Published: 2018
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8. Beam-Target Helicity Asymmetry $E$ in $K^{0}\Lambda$ and $K^{0}\Sigma^0$ Photoproduction on the Neutron

Author: CLAS Collaboration, Ho, D. H., Schumacher, R. A., D'Angelo, A., Deur, A., Fleming, J., Hanretty, C., Kageya, T., Klein, F. J., Klempt, E., Lowry, M. M., Lu, H., Nikonov, V. A., Peng, P., Sandorfi, A. M., Sarantsev, A. V., Strakovsky, I. I., Walford, N. K., Wei, X., Workman, R. L., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Ball, J., Barion, L., Bashkanov, M., Bass, C. D., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Boiarinov, S., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P., Contalbrigo, M., Crede, V., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Laine, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I . J . D., Marchand, D., Markov, N., Mayer, M., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Rehfuss, M., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strauch, S., Taiuti, M., Tan, J. A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Watts, D. P., Weinstein, L. B., Whisnant, C. S., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: We report the first measurements of the $E$ beam-target helicity asymmetry for the $\vec{\gamma} \vec{n} \to K^{0}\Lambda$, and $K^{0}\Sigma^{0}$ channels in the energy range 1.70$\leq W\leq$2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees was used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin $I=0$ and $I=1$ photo-coupling transition amplitudes in pseudoscalar meson photoproduction., Comment: 14 pages, 9 figures; Revised to match published version
Published: 2018
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9. Semi-Inclusive $\pi_0$ target and beam-target asymmetries from 6 GeV electron scattering with CLAS

Author: Jawalkar, S., Koirala, S., Avakian, H., Bosted, P., Griffioen, K. A., Keith, C., Kuhn, S. E., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brock, J., Brooks, W. K., Bultmann, S., Burkert, V. D., Cao, Frank Thanh, Carlin, C., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Ddoge, G., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Garcon, M., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Guidal, M., Guler, N., Guo, L., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McCracken, M. E., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, E., Phelps, W., Pierce, J., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatie, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stankovic, I., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Phenomenology
Abstract: We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic $^{14}$NH$_3$ target, and extracted double and single target spin asymmetries for $ep\rightarrow e^\prime\pi^0X$ in multidimensional bins in four-momentum transfer ($1.0
Published: 2017
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10. Measurement of the helicity asymmetry $E$ in $\omega\to\pi^+\pi^-\pi^0$ photoproduction

Author: Akbar, Z., Roy, P., Park, S., Crede, V., Anisovich, A. V., Denisenko, I., Klempt, E., Nikonov, V. A., Sarantsev, A. V., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Boiarinov, S., Briscoe, W. J., Brock, J., Brooks, W. K., Burkert, V. D., Cao, F. T., Carlin, C., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fradi, A., Garcon, M., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Gleason, C., Gohn, W., Golovach, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Joosten, S., Keith, C. D., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meekins, D. G., Mineeva, T., Mokeev, V., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The double-polarization observable $E$ was studied for the reaction $\gamma p\to p\omega$ using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the longitudinally-polarized frozen-spin target (FROST). The observable was measured from the charged decay mode of the meson, $\omega\to\pi^+\pi^-\pi^0$, using a circularly-polarized tagged-photon beam with energies ranging from the $\omega$ threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found dominant contributions from the $3/2^+$ partial wave near threshold, which is identified with the sub-threshold $N(1720)\,3/2^+$ nucleon resonance. To describe the entire data set, which consisted of $\omega$ differential cross sections and a large variety of polarization observables, further contributions from other nucleon resonances were found to be necessary. With respect to non-resonant mechanisms, $\pi$ exchange in the $t$-channel was found to remain small across the analyzed energy range, while pomeron $t$-channel exchange gradually grew from the reaction threshold to dominate all other contributions above $W \approx 2$ GeV., Comment: 12 pages, 8 figures
Published: 2017
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11. First Exclusive Measurement of Deeply Virtual Compton Scattering off $^4$He: Toward the 3D Tomography of Nuclei

Author: Hattawy, M., Baltzell, N. A., Dupré, R., Hafidi, K., Stepanyan, S., Bültmann, S., De Vita, R., Alaoui, A. El, Fassi, L. El, Egiyan, H., Girod, F. X., Guidal, M., Jenkins, D., Liuti, S., Perrin, Y., Torayev, B., Voutier, E., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Armstrong, Whitney R., Avakian, H., Ball, J., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, Frank Thanh, Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Sanctis, E., Deur, A., Djalali, C., Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Garçon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jiang, H., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McCracken, M. E., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report on the first measurement of the beam-spin asymmetry in the exclusive process of coherent deeply virtual Compton scattering off a nucleus. The experiment used the 6 GeV electron beam from the CEBAF accelerator at Jefferson Lab incident on a pressurized $^4$He gaseous target placed in front of the CEBAF Large Acceptance Spectrometer (CLAS). The scattered electron was detected by CLAS and the photon by a dedicated electromagnetic calorimeter at forward angles. To ensure the exclusivity of the process, a specially designed radial time projection chamber was used to detect the recoiling $^4$He nuclei. We measured beam-spin asymmetries larger than those observed on the free proton in the same kinematic domain. From these, we were able to extract, in a model-independent way, the real and imaginary parts of the only $^4$He Compton form factor, $\cal H_A$. This first measurement of coherent deeply virtual Compton scattering on the $^4$He nucleus, with a fully exclusive final state via nuclear recoil tagging, leads the way toward 3D imaging of the partonic structure of nuclei.
Published: 2017
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12. Differential Cross Section Measurements for $\gamma n\to\pi^-p$ Above the First Nucleon Resonance Region

Author: Mattione, P. T., Carman, D. S., Strakovsky, I. I., Workman, R. L., Kudryavtsev, A. E., Svarc, A., Tarasov, V. E., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Pereira, S. Anefalos, Ball, J., Baltzell, N. A., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Cao, T., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Fradi, A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Murdoch, G., Nadel-Turonski, P., Net, L. A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Strauch, S., Taiuti, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D, Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment
Abstract: The quasi-free $\gamma d\to\pi^{-}p(p)$ differential cross section has been measured with CLAS at photon beam energies $E_\gamma$ from 0.445 GeV to 2.510 GeV (corresponding to $W$ from 1.311 GeV to 2.366 GeV) for pion center-of-mass angles $\cos\theta_\pi^{c.m.}$ from -0.72 to 0.92. A correction for final state interactions has been applied to this data to extract the $\gamma n\to\pi^-p$ differential cross sections. These cross sections are quoted in 8428 $(E_\gamma,\cos\theta_\pi^{c.m.})$ bins, a factor of nearly three increase in the world statistics for this channel in this kinematic range. These new data help to constrain coupled-channel analysis fits used to disentangle the spectrum of $N^*$ resonances and extract their properties. Selected photon decay amplitudes $N^* \to \gamma n$ at the resonance poles are determined for the first time and are reported here.
Published: 2017
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13. The Beam-Target Helicity Asymmetry for $\vec{\gamma} \vec{n} \rightarrow \pi^- p$ in the {\bf{$N^*$} Resonance Region

Author: Ho, D., Peng, P., Bass, C., Collins, P., D'Angelo, A., Deur, A., Fleming, J., Hanretty, C., Kageya, T., Khandaker, M., Klein, F. J., Klempt, E., Laine, V., Lowry, M. M., Lu, H., Nepali, C., Nikonov, V. A., O'Connell, T., Sandorfi, A. M., Sarantsev, A. V., Schumacher, R. A., Strakovsky, I. I., Švarc, A., Walford, N. K., Wei, X., Whisnant, C. S., Workman, R. L., Zonta, I., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Briscoe, W. J., Burkert, V. D., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Crede, V., Dashyan, N., De Sanctis, E., De Vita, R., Djalali, C., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Harrison, N., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I . J . D., Markov, N., McKinnon, B., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Murdoch, G., Niccolai, S., Niculescu, G., Osipenko, M., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Procureur, S., Protopopescu, D., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strauch, S., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Watts, D. P., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment
Abstract: We report the first beam-target double-polarization asymmetries in the $\gamma + n(p) \rightarrow \pi^- + p(p)$ reaction spanning the nucleon resonance region from invariant mass $W$= $1500$ to $2300$ MeV. Circularly polarized photons and longitudinally polarized deuterons in $H\!D$ have been used with the CLAS detector at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the {\it{E}} polarization observable for an effective neutron target. These results have been incorporated into new partial wave analyses, and have led to significant revisions for several $\gamma nN^*$ resonance photo-couplings., Comment: 6 pages, 5 figures; Physical Review Letters - in press
Published: 2017

14. Exclusive $\eta$ electroproduction at $W>2$ GeV with CLAS and transversity generalized parton distributions

Author: CLAS Collaboration, Bedlinskiy, I., Kubarovsky, V., Stoler, P., Adhikari, K. P., Akbar, Z., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Garçon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Hughes, S. M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meziani, Z. E., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Turisini, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Yurov, M., Zachariou, N., Zhang, J., and Zonta, I.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The cross section of the exclusive $\eta$ electroproduction reaction $ep\to e^\prime p^\prime \eta$ was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\eta$ and structure functions $\sigma_U = \sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$, as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. The $\eta$ structure functions are compared with those previously measured for $\pi^0$ at the same kinematics. At low $t$, both $\pi^0$ and $\eta$ are described reasonably well by generalized parton distributions (GPDs) in which chiral-odd transversity GPDs are dominant. The $\pi^0$ and $\eta$ data, when taken together, can facilitate the flavor decomposition of the transversity GPDs., Comment: 16 pages, 16 figures
Published: 2017
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15. Target and beam-target spin asymmetries in exclusive pion electroproduction for $Q^2>1$ GeV$^2$. II. $e p \rightarrow e \pi^0 p$

Author: Bosted, P. E., Kim, A., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Badui, R. A., Ball, J., Balossino, I., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bültmann, S., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Hakobyan, H., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ireland, D. G., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, W., Klei, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Markov, N., Mayer, M., McCracken, M. E., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V. I., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Murdoch, G., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^0$ electroproduction reaction $\gamma^* p \to p \pi^0$, expanding an analysis of the $\gamma^* p \to n \pi^+$ reaction from the same experiment. The results were obtained from scattering of 6 GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Lab. The kinematic range covered is $1.1
Published: 2016
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16. Measurement of Target and Double-spin Asymmetries for the $\vec e\vec p\to e\pi^+ (n)$ Reaction in the Nucleon Resonance Region at Low $Q^2$

Author: Zheng, X., Adhikari, K. P., Bosted, P., Deur, A., Drozdov, V., Fassi, L. El, Kang, Hyekoo, Kovacs, K., Kuhn, S., Long, E., Phillips, S. K., Ripani, M., Slifer, K., Smith, L. C., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chen, J. -P., Chetry, T., Choi, Seonho, Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Djalali, C., Dodge, G. E., Dupre, R., Egiyan, H., Alaoui, A. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovach, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I . J . D., Markov, N., McKinnon, B., Mirazita, M., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Murdoch, G., Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Pisano, S., Pogorelko, O., Price, J. W., Puckett, A. J. R., Raue, B. A., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., and Zhang, J.
Subjects: Nuclear Experiment
Abstract: We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e\pi^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3 and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low $Q^2$ range from $0.0065$ to $0.35$ (GeV$/c$)$^2$. The $Q^2$ access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as $6^\circ$. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models., Comment: 20 pages, 15 figures, to appear in Phys. Rev. C
Published: 2016
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17. Target and Beam-Target Spin Asymmetries in Exclusive $\pi^+$ and $\pi^-$ Electroproduction with 1.6 to 5.7 GeV Electrons

Author: Bosted, P. E., Biselli, A. S., Careccia, S., Dodge, G., Fersch, R., Kuhn, S. E., Pierce, J., Prok, Y., Zheng, X., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Boiarinov, S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fanchini, E., Fedotov, G., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Garçon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guler, N., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., McCracken, M. E., McKinnon, B., Meyer, C. A., Minehart, R., Mirazita, M., Mokeev, V., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Smith, G. D., Sparveris, N., Stankovic, Ivana, Stepanyan, S., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: Beam-target double spin asymmetries and target single-spin asymmetries in exclusive $\pi^+$ and $\pi^-$ electroproduction were obtained from scattering of 1.6 to 5.7 GeV longitudinally polarized electrons from longitudinally polarized protons (for $\pi^+$) and deuterons (for $\pi^-$) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic range covered is $1.11.5$ GeV. Very large target-spin asymmetries are observed for $W>1.6$ GeV. When combined with cross section measurements, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of $Q^2$, for resonances with masses as high as 2.3 GeV., Comment: 47 pages, 24 figures. This is a revised version that was accepted for publication in Phys. Rev. C. in early October, 2016
Published: 2016
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18. Measurement of two-photon exchange effect by comparing elastic $e^\pm p$ cross sections

Author: Rimal, D., Adikaram, D., Raue, B. A., Weinstein, L. B., Arrington, J., Brooks, W. K., Ungaro, M., Adhikari, K. P., Akbar, Z., Pereira, S. Anefalos, Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bennett, R. P., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Bültmann, S., Carman, D. S., Celentano, A., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Joosten, S., Keller, D., Khetarpal, P., Khachatryan, G., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., McKinnon, B., Mestayer, M. D., Mirazita, M., Mokeev, V., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, Ivana, Stepanyan, S., Strauch, S., Sytnik, V., Taiuti, M., Torayev, B., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: [Background] The electromagnetic form factors of the proton measured by unpolarized and polarized electron scattering experiments show a significant disagreement that grows with the squared four momentum transfer ($Q^{2}$). Calculations have shown that the two measurements can be largely reconciled by accounting for the contributions of two-photon exchange (TPE). TPE effects are not typically included in the standard set of radiative corrections since theoretical calculations of the TPE effects are highly model dependent, and, until recently, no direct evidence of significant TPE effects has been observed. [Purpose] We measured the ratio of positron-proton to electron-proton elastic-scattering cross sections in order to determine the TPE contribution to elastic electron-proton scattering and thereby resolve the proton electric form factor discrepancy. [Methods] We produced a mixed simultaneous electron-positron beam in Jefferson Lab's Hall B by passing the 5.6 GeV primary electron beam through a radiator to produce a bremsstrahlung photon beam and then passing the photon beam through a convertor to produce electron/positron pairs. The mixed electron-positron (lepton) beam with useful energies from approximately 0.85 to 3.5 GeV then struck a 30-cm long liquid hydrogen (LH$_2$) target located within the CEBAF Large Acceptance Spectrometer (CLAS). By detecting both the scattered leptons and the recoiling protons we identified and reconstructed elastic scattering events and determined the incident lepton energy. A detailed description of the experiment is presented., Comment: 21 pages, 22 figures
Published: 2016
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19. Target and Double Spin Asymmetries of Deeply Virtual $\pi^0$ Production with a Longitudinally Polarized Proton Target and CLAS

Author: Kim, A., Avakian, H., Burkert, V., Joo, K., Kim, W., Adhikari, K. P., Akbar, Z., Pereira, S. Anefalos, Badui, R. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Bosted, P., Briscoe, W. J., Brooks, W. K., Bültmann, S., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Djalali, C., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Fradi, A., Garçon, M., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hanretty, C., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jiang, H., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mattione, P., McCracken, M. E., McKinnon, B., Mokeev, V., Movsisyan, A, Munevar, E., Nadel-Turonski, P., Net, L. A., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., Zana, L., Zhang, J., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: The target and double spin asymmetries of the exclusive pseudoscalar channel $\vec e\vec p\to ep\pi^0$ were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of $Q^2$, $x_B$, $-t$ and $\phi$. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs $\tilde{H}_T$ and $E_T$, and complement previous measurements of unpolarized structure functions sensitive to the GPDs $H_T$ and $\bar E_T$. These data provide necessary constraints for chiral-odd GPD parametrizations and will strongly influence existing theoretical handbag models.
Published: 2015
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20. Measurement of two-photon exchange effect by comparing elastic e±p cross sections

Author: Rimal, D, Adikaram, D, Raue, BA, Weinstein, LB, Arrington, J, Brooks, WK, Ungaro, M, Adhikari, KP, Afanasev, AV, Akbar, Z, Pereira, S Anefalos, Badui, RA, Ball, J, Baltzell, NA, Battaglieri, M, Batourine, V, Bedlinskiy, I, Biselli, AS, Boiarinov, S, Briscoe, WJ, Bültmann, S, Burkert, VD, Carman, DS, Celentano, A, Chetry, T, Ciullo, G, Clark, L, Colaneri, L, Cole, PL, Compton, N, Contalbrigo, M, Cortes, O, Crede, V, D'Angelo, A, Dashyan, N, De Vita, R, Deur, A, Djalali, C, Dupre, R, Egiyan, H, Alaoui, A El, Fassi, L El, Eugenio, P, Fanchini, E, Fedotov, G, Fersch, R, Filippi, A, Fleming, JA, Forest, TA, Fradi, A, Gevorgyan, N, Ghandilyan, Y, Gilfoyle, GP, Giovanetti, KL, Girod, FX, Gleason, C, Gohn, W, Golovatch, E, Gothe, RW, Griffioen, KA, Guo, L, Hafidi, K, Hanretty, C, Harrison, N, Hattawy, M, Heddle, D, Hicks, K, Holtrop, M, Hughes, SM, Ilieva, Y, Ireland, DG, Ishkhanov, BS, Isupov, EL, Jenkins, D, Jiang, H, Joosten, S, Keller, D, Khachatryan, G, Khandaker, M, Kim, W, Klein, A, Klein, FJ, Kubarovsky, V, Kuhn, SE, Kuleshov, SV, Lanza, L, Lenisa, P, Livingston, K, Lu, HY, MacGregor, IJD, Markov, N, McKinnon, B, Mestayer, MD, Mirazita, M, Mokeev, V, Movsisyan, A, Munevar, E, Camacho, C Munoz, Nadel-Turonski, P, and Ni, A
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, nucl-ex, Nuclear and plasma physics
Abstract: Background: The electromagnetic form factors of the proton measured by unpolarized and polarized electron scattering experiments show a significant disagreement that grows with the squared four-momentum transfer (Q2). Calculations have shown that the two measurements can be largely reconciled by accounting for the contributions of two-photon exchange (TPE). TPE effects are not typically included in the standard set of radiative corrections since theoretical calculations of the TPE effects are highly model dependent, and, until recently, no direct evidence of significant TPE effects has been observed. Purpose: We measured the ratio of positron-proton to electron-proton elastic-scattering cross sections in order to determine the TPE contribution to elastic electron-proton scattering and thereby resolve the proton electric form factor discrepancy. Methods: We produced a mixed simultaneous electron-positron beam in Jefferson Lab's Hall B by passing the 5.6-GeV primary electron beam through a radiator to produce a bremsstrahlung photon beam and then passing the photon beam through a convertor to produce electron-positron pairs. The mixed electron-positron (lepton) beam with useful energies from approximately 0.85 to 3.5 GeV then struck a 30-cm-long liquid hydrogen (LH2) target located within the CEBAF Large Acceptance Spectrometer (CLAS). By detecting both the scattered leptons and the recoiling protons, we identified and reconstructed elastic scattering events and determined the incident lepton energy. A detailed description of the experiment is presented. Results: We present previously unpublished results for the quantity R2γ, the TPE correction to the elastic-scattering cross section, at Q2≈0.85 and 1.45 GeV2 over a large range of virtual photon polarization ?. Conclusions: Our results, along with recently published results from VEPP-3, demonstrate a nonzero contribution from TPE effects and are in excellent agreement with the calculations that include TPE effects and largely reconcile the form-factor discrepancy up to Q2≈2GeV2. These data are consistent with an increase in R2γ with decreasing ? at Q2≈0.85 and 1.45 GeV2. There are indications of a slight increase in R2γ with Q2.
Published: 2017

21. A search for baryon- and lepton-number violating decays of $\Lambda$ hyperons using the CLAS detector at Jefferson Laboratory

Author: McCracken, M. E., Bellis, M., Adhikari, K. P., Adikaram, D., Akbar, Z., Pereira, S. Anefalos, Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, E., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Garillon, B., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mayer, M., McKinnon, B., Mestayer, M. D., Meyer, C. A., Mirazita, M., Mokeev, V., Moody, C. I., Moriya, K., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Park, K., Pasyuk, E., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Sokhan, D., Sparveris, N., Stoler, P., Strakovsky, I. I., Strauch, S., Sytnik, V., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We present a search for ten baryon-number violating decay modes of $\Lambda$ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state ($\Lambda \rightarrow m \ell$) and conserve either the sum or the difference of baryon and lepton number ($B \pm L$). The tenth decay mode ($\Lambda \rightarrow \bar{p}\pi^+$) represents a difference in baryon number of two units and no difference in lepton number. We observe no significant signal and set upper limits on the branching fractions of these reactions in the range $(4-200)\times 10^{-7}$ at the $90\%$ confidence level., Comment: 12 pages, 7 figures (color)
Published: 2015
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22. Precise Determination of the Deuteron Spin Structure at Low to Moderate $Q^2$ with CLAS and Extraction of the Neutron Contribution

Author: Guler, N., Fersch, R. G., Kuhn, S. E., Bosted, P., Griffioen, K. A., Keith, C., Minehart, R., Prok, Y., Adhikari, K. P., Adikaram, D., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Briscoe, W. J., Brooks, W. K., Bultmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Colaneri, L., Cole, P. L., Contalbrigo, M., Crabb, D., Crede, V., Angelo, A. D, Dashyan, N., Deur, A., Djalali, C., Dodge, G. E., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Fleming, J. A., Forest, T. A., Garillon, B., Garcon, M., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Golovatch, E., Gothe, R. W., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Hughes, S. M., Hyde, C. E., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Livingston, K., Lu, H. Y., MacGregor, I. J. D., McKinnon, B., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Park, K., Pasyuk, E., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatie, F., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Simonyan, A., Skorodumina, Iu., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Sytnik, V., Tian, Ye, Tkachenko, S., Ungaro, M., Voutier, E., Walford, N. K., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: We present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron ($^{15}$ND$_3$) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry $A_1^d$ and the polarized structure function $g_1^d$ were extracted over a wide kinematic range (0.05 GeV$^2 < Q^2 <$ 5 GeV$^2$ and 0.9 GeV $< W <$ 3 GeV). We use an unfolding procedure and a parametrization of the corresponding proton results to extract from these data the polarized structure functions $A_1^n$ and $g_1^n$ of the (bound) neutron, which are so far unknown in the resonance region, $W < 2$ GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large $x$, a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the Operator Product Expansion., Comment: To be published in Phys. Rev. C
Published: 2015
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23. Precision measurements of $g_1$ of the proton and the deuteron with 6 GeV electrons

Author: Prok, Y., Bosted, P., Kvaltine, N., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Biselli, A. S., Bono, J., Briscoe, W. J., Brock, J., Brooks, W. K., Bültmann, S., Burkert, V. D., Carlin, C., Carman, D. S., Celentano, A., Chandavar, S., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crabb, D., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Forest, T. A., Garcon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Giovanetti, K. L., Goetz, J. T., Gohn, W., Gothe, R. W., Griffioen, K. A., Guegan, B., Guler, N., Haffidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jawalkar, S., Jiang, X., Jo, H. S., Joo, K., Kalantarians, N., Keith, C., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J. D., Markov, N., Mayee, M., McKinnon, B., Meekins, D., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Peng, P., Phillips, J. J., Pierce, J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Rimal, D., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Smith, C., Smith, G., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Tang, W., Tkachenko, S., Ungaro, M., Vernarsky, B ., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D . P., Weinstein, L. B., Zachariou, N., Zana, L., Zhang, J., Zhao, B., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: The inclusive polarized structure functions of the proton and deuteron, g1p and g1d, were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory. Electrons scattered at lab angles between 18 and 45 degrees were detected using the CEBAF Large Acceptance Spectrometer (CLAS). For the usual DIS kinematics, Q^2>1 GeV^2 and the final-state invariant mass W>2 GeV, the ratio of polarized to unpolarized structure functions g1/F1 is found to be nearly independent of Q^2 at fixed x. Significant resonant structure is apparent at values of W up to 2.3 GeV. In the framework of perturbative QCD, the high-W results can be used to better constrain the polarization of quarks and gluons in the nucleon, as well as high-twist contributions.
Published: 2014
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24. Demonstration of a novel technique to measure two-photon exchange effects in elastic $e^\pm p$ scattering

Author: Moteabbed, M., Niroula, M., Raue, B. A., Weinstein, L. B., Adikaram, D., Arrington, J., Brooks, W. K., Lachniet, J., Rimal, Dipak, Ungaro, M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bennett, R. P., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Cole, P. L., Collins, P., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lewis, S., Lu, H. Y., MacCormick, M., MacGregor, I . J . D., Martinez, D., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moriya, K., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S., Strauch, S., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Voskanyan, H., Voutier, E., Walford, N. K., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations of TPE corrections have significant model dependence, and there is limited direct experimental evidence for such corrections. We present the results of a new experimental technique for making direct $e^\pm p$ comparisons, which has the potential to make precise measurements over a broad range in $Q^2$ and scattering angles. We use the Jefferson Lab electron beam and the Hall B photon tagger to generate a clean but untagged photon beam. The photon beam impinges on a converter foil to generate a mixed beam of electrons, positrons, and photons. A chicane is used to separate and recombine the electron and positron beams while the photon beam is stopped by a photon blocker. This provides a combined electron and positron beam, with energies from 0.5 to 3.2 GeV, which impinges on a liquid hydrogen target. The large acceptance CLAS detector is used to identify and reconstruct elastic scattering events, determining both the initial lepton energy and the sign of the scattered lepton. The data were collected in two days with a primary electron beam energy of only 3.3 GeV, limiting the data from this run to smaller values of $Q^2$ and scattering angle. Nonetheless, this measurement yields a data sample for $e^\pm p$ with statistics comparable to those of the best previous measurements. We have shown that we can cleanly identify elastic scattering events and correct for the difference in acceptance for electron and positron scattering. The final ratio of positron to electron scattering: $R=1.027\pm0.005\pm0.05$ for $=0.206$ GeV$^2$ and $0.830\leq \epsilon\leq 0.943$.
Published: 2013
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25. Measurement of Charge Multiplicity Asymmetry Correlations in High Energy Nucleus-Nucleus Collisions at 200 GeV

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Powell, C. B., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at 200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, $\Delta$, between the like- and unlike-sign up/down $-$ left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic $v^{\rm obs}_{2}$), where $\Delta=(1.3\pm1.4({\rm stat})^{+4.0}_{-1.0}({\rm syst}))\times10^{-5}+(3.2\pm0.2({\rm stat})^{+0.4}_{-0.3}({\rm syst}))\times10^{-3}v^{\rm obs}_{2}$ for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed., Comment: 27 pages, 25 figures, 2 tables
Published: 2013
Full Text: View/download PDF

26. Fluctuations of charge separation perpendicular to the event plane and local parity violation in sqrt(sNN)=200 GeV Au+Au collisions at RHIC

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Previous experimental results based on data (15 million events) collected by the STAR detector at RHIC suggest event-by-event charge separation fluctuations perpendicular to the event plane in non-central heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high statistics 200 GeV Au+Au collisions data set (57 million events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same and opposite charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion., Comment: 10 pages, 9 figures
Published: 2013

27. Freeze-out Dynamics via Charged Kaon Femtoscopy in sqrt(sNN)=200 GeV Central Au+Au Collisions

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We present measurements of three-dimensional correlation functions of like-sign low transverse momentum kaon pairs from sqrt(sNN)=200 GeV Au+Au collisions. A Cartesian surface-spherical harmonic decomposition technique was used to extract the kaon source function. The latter was found to have a three-dimensional Gaussian shape and can be adequately reproduced by Therminator event generator simulations with resonance contributions taken into account. Compared to the pion one, the kaon source function is generally narrower and does not have the long tail along the pair transverse momentum direction. The kaon Gaussian radii display a monotonic decrease with increasing transverse mass m_T over the interval of 0.55<=m_T<=1.15 GeV/c^2. While the kaon radii are adequately described by the m_T-scaling in the outward and sideward directions, in the longitudinal direction the lowest m_T value exceeds the expectations from a pure hydrodynamical model prediction., Comment: 8 pages, 4 figures
Published: 2013
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28. Transverse Polarization of $\Sigma^{+}(1189)$ in Photoproduction on a Hydrogen Target in CLAS

Author: Nepali, C. S., Amaryan, M., Adhikari, K. P., Aghasyan, M., Pereira, S. Anefalos, Baghdasaryan, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Collins, P., Contalbrigo, M., Crede, V., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Alaoui, A. El, Fassi, L. El, Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gabrielyan, M. Y., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Rimal, D., Ripani, M., Ritchie, B. G., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Torayev, B., Vernarsky, B., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: Experimental results on the $\Sigma^+(1189)$ hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson laboratory are presented. The $\Sigma^+(1189)$ was reconstructed in the exclusive reaction $\gamma+p\rightarrow K^{0}_{S} + \Sigma^+(1189)$ via the $\Sigma^{+} \to p \pi^{0}$ decay mode. The $K^{0}_S$ was reconstructed in the invariant mass of two oppositely charged pions with the $\pi^0$ identified in the missing mass of the detected $p\pi^+\pi^-$ final state. Experimental data were collected in the photon energy range $E_{\gamma}$ = 1.0-3.5 GeV ($\sqrt{s}$ range 1.66-2.73 GeV). We observe a large negative polarization of up to 95%. As the mechanism of transverse polarization of hyperons produced in unpolarized photoproduction experiments is still not well understood, these results will help to distinguish between different theoretical models on hyperon production and provide valuable information for the searches of missing baryon resonances., Comment: pages 11
Published: 2013
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29. System size dependence of transverse momentum correlations at $\sqrt{s_{NN}}=$ 62.4 and 200 GeV at the BNL Relativistic Heavy Ion Collider

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We present a study of the average transverse momentum ($p_t$) fluctuations and $p_t$ correlations for charged particles produced in Cu+Cu collisions at midrapidity for $\sqrt{s_{NN}} =$ 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the $p_t$ correlation results have been studied as functions of the collision centralities, the ranges in $p_t$, the pseudorapidity $\eta$, and the azimuthal angle $\phi$. The square root of the measured $p_t$ correlations when scaled by mean $p_t$ is found to be independent of both colliding beam energy and system size studied. Transport-based model calculations are found to have a better quantitative agreement with the measurements compared to models which incorporate only jetlike correlations., Comment: 12 pages and 9 figures. Published in Physical Review C
Published: 2013
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30. Observation of an energy-dependent difference in elliptic flow between particles and anti-particles in relativistic heavy ion collisions

Author: Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Elliptic flow ($v_{2}$) values for identified particles at mid-rapidity in Au+Au collisions, measured by the STAR experiment in the Beam Energy Scan at RHIC at $\sqrt{s_{NN}}=$ 7.7--62.4 GeV, are presented. A beam-energy dependent difference of the values of $v_{2}$ between particles and corresponding anti-particles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and anti-particles are not consistent with the universal number-of-constituent-quark (NCQ) scaling of $v_{2}$ that was observed at $\sqrt{s_{NN}}=$ 200 GeV.
Published: 2013
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31. Elliptic flow of identified hadrons in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7--62.4 GeV

Author: Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: Measurements of the elliptic flow, $v_{2}$, of identified hadrons ($\pi^{\pm}$, $K^{\pm}$, $K_{s}^{0}$, $p$, $\bar{p}$, $\phi$, $\Lambda$, $\bar{\Lambda}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$) in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV are presented. The measurements were done at mid-rapidity using the Time Projection Chamber and the Time-of-Flight detectors of the STAR experiment during the Beam Energy Scan program at RHIC. A significant difference in the $v_{2}$ values for particles and the corresponding anti-particles was observed at all transverse momenta for the first time. The difference increases with decreasing center-of-mass energy, $\sqrt{s_{NN}}$ (or increasing baryon chemical potential, $\mu_{B}$) and is larger for the baryons as compared to the mesons. This implies that particles and anti-particles are no longer consistent with the universal number-of-constituent quark (NCQ) scaling of $v_{2}$ that was observed at $\sqrt{s_{NN}}=$ 200 GeV. However, for the group of particles NCQ scaling at $(m_{T}-m_{0})/n_{q}>$ 0.4 GeV/$c^{2}$ is not violated within $\pm$10%. The $v_{2}$ values for $\phi$ mesons at 7.7 and 11.5 GeV are approximately two standard deviations from the trend defined by the other hadrons at the highest measured $p_{T}$ values.
Published: 2013
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32. Third Harmonic Flow of Charged Particles in Au+Au Collisions at sqrtsNN = 200 GeV

Author: STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L. -X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I. -K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v_3, known as triangular flow. The analysis is for charged particles in Au+Au collisions at sqrtsNN = 200 GeV, based on data from the STAR experiment at the Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are reported as a function of transverse momentum and centrality. A large dependence on the pseudorapidity gap is found. Results are compared with other experiments and model calculations., Comment: 12 pages, 12 figures
Published: 2013
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33. Near Threshold Neutral Pion Electroproduction at High Momentum Transfers and Generalized Form Factors

Author: Khetarpal, P., Stoler, P., Aznauryan, I. G., Kubarovsky, V., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Charles, G., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Fradi, A., Gabrielyan, M. Y., Garçon, M., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kuleshov, S. V., Kvaltine, N. D., Lewis, S., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Saylor, N. A., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tkachenko, S., Ungaro, M., Vernarsky, B., Voskanyan, H., Voutier, E., Walford, N. K., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: We report the measurement of near threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range $Q^2$ from 2 to 4.5 GeV$^2$ and $W$ from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles $E_{0+}$ and $S_{0+}$ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors $G_1^{\pi^0 p}(Q^2)$ and $G_2^{\pi^0 p}(Q^2)$. The data are compared to these generalized form factors and the results for $G_1^{\pi^0 p}(Q^2)$ are found to be in good agreement with the LCSR predictions, but the level of agreement with $G_2^{\pi^0 p}(Q^2)$ is poor., Comment: 17 pages, 18 figures, Journal article (Physical Review C)
Published: 2012
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34. Single Spin Asymmetry $A_N$ in Polarized Proton-Proton Elastic Scattering at $\sqrt{s}=200$ GeV

Author: STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report a high precision measurement of the transverse single spin asymmetry $A_N$ at the center of mass energy $\sqrt{s}=200$ GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The $A_N$ was measured in the four-momentum transfer squared $t$ range $0.003 \leqslant |t| \leqslant 0.035$ $\GeVcSq$, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of $A_N$ and its $t$-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this $\sqrt{s}$, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering., Comment: 12 pages, 6 figures
Published: 2012
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35. Transverse Single-Spin Asymmetry and Cross-Section for pi0 and eta Mesons at Large Feynman-x in Polarized p+p Collisions at sqrt(s)=200 GeV

Author: The STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Bannerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr, C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Measurements of the differential cross-section and the transverse single-spin asymmetry, A_N, vs. x_F for pi0 and eta mesons are reported for 0.4 < x_F < 0.75 at an average pseudorapidity of 3.68. A data sample of approximately 6.3 pb^{-1} was analyzed, which was recorded during p+p collisions at sqrt{s} = 200 GeV by the STAR experiment at RHIC. The average transverse beam polarization was 56%. The cross-section for pi0 is consistent with a perturbative QCD prediction, and the eta/pi0 cross-section ratio agrees with previous mid-rapidity measurements. For 0.55 < x_F < 0.75, A_N for eta (0.210 +- 0.056) is 2.2 standard deviations larger than A_N for pi0 (0.081 +- 0.016)., Comment: 7 pages, 5 figures, Submitted to Phys. Rev. D R.C
Published: 2012
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36. Longitudinal and transverse spin asymmetries for inclusive jet production at mid-rapidity in polarized p+p collisions at sqrt{s}=200 GeV

Author: The STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kowalik, K., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Millane, J., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Sakuma, T., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Sarsour, M., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: We report STAR measurements of the longitudinal double-spin asymmetry A_LL, the transverse single-spin asymmetry A_N, and the transverse double-spin asymmetries A_Sigma and A_TT for inclusive jet production at mid-rapidity in polarized p+p collisions at a center-of-mass energy of sqrt{s} = 200 GeV. The data represent integrated luminosities of 7.6 /pb with longitudinal polarization and 1.8 /pb with transverse polarization, with 50-55% beam polarization, and were recorded in 2005 and 2006. No evidence is found for the existence of statistically significant jet A_N, A_Sigma, or A_TT at mid-rapidity. Recent model calculations indicate the A_N results may provide new limits on the gluon Sivers distribution in the proton. The asymmetry A_LL significantly improves the knowledge of gluon polarization in the nucleon., Comment: 18 pages, 16 figures, 8 tables
Published: 2012

37. Measurements of $D^{0}$ and $D^{*}$ Production in $p$ + $p$ Collisions at $\sqrt{s}$ = 200 GeV

Author: STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report measurements of charmed-hadron ($D^{0}$, $D^{*}$) production cross sections at mid-rapidity in $p$ + $p$ collisions at a center-of-mass energy of 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via the hadronic decays $D^{0}\rightarrow K^{-}\pi^{+}$, $D^{*+}\rightarrow D^{0}\pi^{+}\rightarrow K^{-}\pi^{+}\pi^{+}$ and their charge conjugates, covering the $p_T$ range of 0.6$-$2.0 GeV/$c$ and 2.0$-$6.0 GeV/$c$ for $D^{0}$ and $D^{*+}$, respectively. From this analysis, the charm-pair production cross section at mid-rapidity is $d\sigma/dy|_{y=0}^{c\bar{c}}$ = 170 $\pm$ 45 (stat.) $^{+38}_{-59}$ (sys.) $\mu$b. The extracted charm-pair cross section is compared to perturbative QCD calculations. The transverse momentum differential cross section is found to be consistent with the upper bound of a Fixed-Order Next-to-Leading Logarithm calculation., Comment: 15 pages, 16 figures. Revised version submitted to Phys. Rev. D
Published: 2012
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38. Di-electron spectrum at mid-rapidity in $p+p$ collisions at $\sqrt{s} = 200$ GeV

Author: Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.
Subjects: Nuclear Experiment
Abstract: We report on mid-rapidity mass spectrum of di-electrons and cross sections of pseudoscalar and vector mesons via $e^{+}e^{-}$ decays, from $\sqrt{s} = 200$ GeV $p+p$ collisions, measured by the large acceptance experiment STAR at RHIC. The ratio of the di-electron continuum to the combinatorial background is larger than 10% over the entire mass range. Simulations of di-electrons from light-meson decays and heavy-flavor decays (charmonium and open charm correlation) are found to describe the data. The extracted $\omega\rightarrow e^{+}e^{-}$ invariant yields are consistent with previous measurements. The mid-rapidity yields ($dN/dy$) of $\phi$ and $J/\psi$ are extracted through their di-electron decay channels and are consistent with the previous measurements of $\phi\rightarrow K^{+}K^{-}$ and $J/\psi\rightarrow e^{+}e^{-}$. Our results suggest a new upper limit of the branching ratio of the $\eta \rightarrow e^{+}e^{-}$ of $1.7\times10^{-5}$ at 90% confidence level., Comment: 15 pages, 17 figures, 4 tables. Published
Published: 2012
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39. Measurement of the $W \to e \nu$ and $Z/\gamma^* \to e^+e^-$ Production Cross Sections at Mid-rapidity in Proton-Proton Collisions at $\sqrt{s}$ = 500 GeV

Author: STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Banerjee, Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report measurements of the charge-separated $W^{+(-)} \to e^{+(-)} + \nu_e(\bar{\nu}_e)$ and $Z/\gamma^* \to e^+e^-$ production cross sections at mid-rapidity in proton-proton collisions at $\sqrt{s}$ = 500 GeV. These results are based on 13.2 pb$^{-1}$ of data recorded in 2009 by the STAR detector at RHIC. Production cross sections for W bosons that decay via the $e \nu$ channel were measured to be $\sigma(pp \to W^+ X) \cdot BR(W^+ \to e^+ \nu_e)$ = 117.3 \pm 5.9(stat) \pm 6.2(syst) \pm 15.2(lumi) pb, and $\sigma(pp \to W^- X) \cdot BR(W^- \to e^- \bar{\nu}_e)$ = 43.3 \pm 4.6(stat) \pm 3.4(syst) \pm 5.6(lumi) pb. For $Z/\gamma^*$ production, $\sigma(pp \to Z/\gamma^* X) \cdot BR(Z/\gamma^* \to e^+ e^-)$ = 7.7 \pm 2.1(stat) $^{+0.5}_{-0.9}$(syst) \pm 1.0(lumi) pb for di-lepton invariant masses $m_{e^+e^-}$ between 70 and 110 GeV/$c^2$. First measurements of the W cross section ratio, $\sigma(pp \to W^+ X) / \sigma(pp \to W^- X)$, at $\sqrt{s}$ = 500 GeV are also reported. Theoretical predictions, calculated using recent parton distribution functions, are found to agree with the measured cross sections., Comment: 14 pages, 12 figures, submitted to Physical Review D
Published: 2011
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40. Energy and system-size dependence of two- and four-particle $v_2$ measurements in heavy-ion collisions at RHIC and their implications on flow fluctuations and nonflow

Author: The STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Ghosh, P., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., de Souza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We present STAR measurements of azimuthal anisotropy by means of the two- and four-particle cumulants $v_2$ ($v_2\{2\}$ and $v_2\{4\}$) for Au+Au and Cu+Cu collisions at center of mass energies $\sqrt{s_{_{\mathrm{NN}}}} = 62.4$ and 200 GeV. The difference between $v_2\{2\}^2$ and $v_2\{4\}^2$ is related to $v_{2}$ fluctuations ($\sigma_{v_2}$) and nonflow $(\delta_{2})$. We present an upper limit to $\sigma_{v_2}/v_{2}$. Following the assumption that eccentricity fluctuations $\sigma_{\epsilon}$ dominate $v_2$ fluctuations $\frac{\sigma_{v_2}}{v_2} \approx \frac{\sigma_{\epsilon}}{\epsilon}$ we deduce the nonflow implied for several models of eccentricity fluctuations that would be required for consistency with $v_2\{2\}$ and $v_2\{4\}$. We also present results on the ratio of $v_2$ to eccentricity., Comment: 15 pages, 12 Figures
Published: 2011
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41. System size and energy dependence of near-side di-hadron correlations

Author: STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bombara, M., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., Didenko, L., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gaillard, L., Gangadharan, D. R., Geurts, F., Ghosh, P., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Jones, P. G., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nattrass, C., Nasim, Md., Nayak, T. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbæ, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: Two-particle azimuthal ($\Delta\phi$) and pseudorapidity ($\Delta\eta$) correlations using a trigger particle with large transverse momentum ($p_T$) in $d$+Au, Cu+Cu and Au+Au collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV and 200~GeV from the STAR experiment at RHIC are presented. The \ns correlation is separated into a jet-like component, narrow in both $\Delta\phi$ and $\Delta\eta$, and the ridge, narrow in $\Delta\phi$ but broad in $\Delta\eta$. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated $p_T$. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at $\sqrt{s_{{NN}}}$ = 200 GeV, is also found in Cu+Cu collisions and in collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV, but is found to be substantially smaller at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV than at $\sqrt{s_{{NN}}}$ = 200 GeV for the same average number of participants ($ \langle N_{\mathrm{part}}\rangle$). Measurements of the ridge are compared to models., Comment: 17 pages, 14 figures, submitted to Phys. Rev. C
Published: 2011
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42. Directed and elliptic flow of charged particles in Cu+Cu collisions at $\sqrt{\bm {s_{NN}}} =$ 22.4 GeV

Author: Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Beavis, D. R., Behera, N. K., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Knospe, A. G., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lima, 1 L. M., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nayak, T. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schaub, J., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: This paper reports results for directed flow $v_{1}$ and elliptic flow $v_{2}$ of charged particles in Cu+Cu collisions at $\sqrt{s_{NN}}=$ 22.4 GeV at the Relativistic Heavy Ion Collider. The measurements are for the 0-60% most central collisions, using charged particles observed in the STAR detector. Our measurements extend to 22.4 GeV Cu+Cu collisions the prior observation that $v_1$ is independent of the system size at 62.4 and 200 GeV, and also extend the scaling of $v_1$ with $\eta/y_{\rm beam}$ to this system. The measured $v_2(p_T)$ in Cu+Cu collisions is similar for $\sqrt{s_{NN}} = 22.4-200$ GeV. We also report a comparison with results from transport model (UrQMD and AMPT) calculations. The model results do not agree quantitatively with the measured $v_1(\eta), v_2(p_T)$ and $v_2(\eta)$., Comment: 10 pages,9 figures: Introduction part of the paper is expanded, Fig 9 is changed slightly, more discussion on summary
Published: 2011
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43. Anomalous centrality evolution of two-particle angular correlations from Au-Au collisions at $\sqrt{s_{\rm NN}}$ = 62 and 200 GeV

Author: STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schaub, J., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., de Souza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: We present two-dimensional (2D) two-particle angular correlations on relative pseudorapidity $\eta$ and azimuth $\phi$ for charged particles from Au-Au collisions at $\sqrt{s_{\rm NN}} = 62$ and 200 GeV with transverse momentum $p_t \geq 0.15$ GeV/$c$, $|\eta| \leq 1$ and $2\pi$ azimuth. Observed correlations include a {same-side} (relative azimuth $< \pi/2$) 2D peak, a closely-related away-side azimuth dipole, and an azimuth quadrupole conventionally associated with elliptic flow. The same-side 2D peak and away-side dipole are explained by semihard parton scattering and fragmentation (minijets) in proton-proton and peripheral nucleus-nucleus collisions. Those structures follow N-N binary-collision scaling in Au-Au collisions until mid-centrality where a transition to a qualitatively different centrality trend occurs within a small centrality interval. Above the transition point the number of same-side and away-side correlated pairs increases rapidly {relative to} binary-collision scaling, the $\eta$ width of the same-side 2D peak also increases rapidly ($\eta$ elongation) and the $\phi$ width actually decreases significantly. Those centrality trends are more remarkable when contrasted with expectations of jet quenching in a dense medium. Observed centrality trends are compared to {\sc hijing} predictions and to the expected trends for semihard parton scattering and fragmentation in a thermalized opaque medium. We are unable to reconcile a semihard parton scattering and fragmentation origin for the observed correlation structure and centrality trends with heavy ion collision scenarios which invoke rapid parton thermalization. On the other hand, if the collision system is effectively opaque to few-GeV partons the observations reported here would be inconsistent with a minijet picture., Comment: 26 pages, 8 figures, 2 tables
Published: 2011
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44. Strangeness Enhancement in Cu+Cu and Au+Au Collisions at \sqrt{s_{NN}} = 200 GeV

Author: STAR Collaboration, Agakishiev, H., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Beavis, D. R., Behera, N. K., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geromitsos, A., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jones, P. G., Jena, C., Jin, F., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Knospe, A. G., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Kurnadi, P., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Naglis, M., Nandi, B. K., Nayak, T. K., Netrakanti, P. K., Nelson, J. M., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Rose, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sakai, S., Sakrejda, I., Sakuma, T., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Tram, V. N., Trentalange, S., Tribble, R. E., Tribedy, P., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbæk, F., Viyogi, Y. P., Vokal, S., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, J., Zhong, C., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: We report new STAR measurements of mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$ particles in Cu+Cu collisions at \sNN{200}, and mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$ particles in Au+Au at \sNN{200}. We show that at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parameterization based on the fraction of participants that undergo multiple collisions.
Published: 2011
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45. Studies of di-jet survival and surface emission bias in Au+Au collisions via angular correlations with respect to back-to-back leading hadrons

Author: Agakishiev, H., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Beavis, D. R., Behera, N. K., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geromitsos, A., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O. G., Grosnick, D., Guertin, S. M., Gupta, A., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Knospe, A. G., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Kurnadi, P., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nayak, T. K., Netrakanti, P. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Rose, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sakai, S., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Tram, V. N., Trentalange, S., Tribble, R. E., Tribedy, P., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, J., Zhong, C., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: We report first results from an analysis based on a new multi-hadron correlation technique, exploring jet-medium interactions and di-jet surface emission bias at RHIC. Pairs of back-to-back high transverse momentum hadrons are used for triggers to study associated hadron distributions. In contrast with two- and three-particle correlations with a single trigger with similar kinematic selections, the associated hadron distribution of both trigger sides reveals no modification in either relative pseudo-rapidity or relative azimuthal angle from d+Au to central Au+Au collisions. We determine associated hadron yields and spectra as well as production rates for such correlated back-to-back triggers to gain additional insights on medium properties., Comment: By the STAR Collaboration. 6 pages, 2 figures
Published: 2011
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46. Measurements of Dihadron Correlations Relative to the Event Plane in Au+Au Collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV

Author: Agakishiev, H., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Beavis, D. R., Behera, N. K., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sanchez, M. Calderon de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Feng, A., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geromitsos, A., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hofmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Knospe, A. G., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Kurnadi, P., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Naglis, M., Nandi, B. K., Nayak, T. K., Netrakanti, P. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, Ohlson, Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Rose, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sakai, S., Sakrejda, I., Sakuma, T., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Tram, V. N., Trentalange, S., Tribble, R. E., Tribedy, Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, J., Zhong, C., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: Dihadron azimuthal correlations containing a high transverse momentum ($p_T$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to p+p and d+Au collisions. The modification increases with the collision centrality, suggesting a path-length or energy density dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20-60%) Au+Au collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\phi_s=|\phi_t-\psi_{\rm EP}|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $p_T$. The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (ZYAM), are described. The correlation results are first discussed with subtraction of the even harmonic (elliptic and quadrangular) flow backgrounds. The away-side correlation is strongly modified, and the modification varies with $\phi_s$, with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity $\Delta\eta$ correlation) appears to drop with increasing $\phi_s$ while the jet-like component remains approximately constant. The correlation functions are further studied with subtraction of odd harmonic triangular flow background arising from fluctuations. It is found that the triangular flow, while responsible for the majority of the amplitudes, is not sufficient to explain the $\phi_s$-dependence of the ridge or the away-side double-peak structure. ..., Comment: 54 pages, 40 figures, 6 tables. As published
Published: 2010
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47. An Experimental Exploration of the QCD Phase Diagram: The Search for the Critical Point and the Onset of De-confinement

Author: STAR Collaboration, Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Anderson, B. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Baumgart, S., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., Bonner, B. E., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., CalderóndelaBarcaSánchez, M., Catu, O., Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Clarke, R. F., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Das, D., Dash, S., DavilaLeyva, A., DeSilva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., DerradideSouza, R., Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., DuttaMazumdar, M. R., Efimov, L. G., Elhalhuli, E., Elnimr, M., Engelage, J., Eppley, G., Erazmus, B., Estienne, M., Eun, L., Evdokimov, O., Fachini, P., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Ganti, M. S., Garcia, E. J., Solis, Geromitsos, A., Geurts, F., Ghazikhanian, V., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., Gupta, N., Guryn, W., Haag, B., Hamed, A., Han, LX., Harris, J. W., HaysWehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffman, A. M., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Jones, C. L., Jones, P. G., Joseph, J., Judd, E. G., Kabana, S., Kajimoto, K., Kang, K., Kapitan, J., Kauder, K., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Klein, S. R., Knospe, A. G., Kocoloski, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Kurnadi, P., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, H., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lin, G., Lindenbaum, S. J., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Nandi, B. K., Nattrass, C., Nayak, T. K., Nelson, J. M., Netrakanti, P. K., Ng, M. J., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Peitzmann, T., Perevoztchikov, V., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Rose, A., Roy, C., Ruan, L., Sahoo, R., Sakai, S., Sakrejda, I., Sakuma, T., Salur, S., Sandweiss, J., Sangaline, E., Schambach, J., Scharenberg, R. P., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Sorensen, P., Sowinski, J., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., SzantodeToledo, A., Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Timoshenko, S., Tlusty, D., Tokarev, M., Tram, V. N., Trentalange, S., Tribble, R. E., Tsai, O. D., Ulery, J., Ullrich, T., Underwood, D. G., VanBuren, G., vanLeeuwen, M., vanNieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., WhittenJr., C., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xie, W., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, IK., Yue, Q., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, J., Zhong, C., Zhou, J., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: The QCD phase diagram lies at the heart of what the RHIC Physics Program is all about. While RHIC has been operating very successfully at or close to its maximum energy for almost a decade, it has become clear that this collider can also be operated at lower energies down to 5 GeV without extensive upgrades. An exploration of the full region of beam energies available at the RHIC facility is imperative. The STAR detector, due to its large uniform acceptance and excellent particle identification capabilities, is uniquely positioned to carry out this program in depth and detail. The first exploratory beam energy scan (BES) run at RHIC took place in 2010 (Run 10), since several STAR upgrades, most importantly a full barrel Time of Flight detector, are now completed which add new capabilities important for the interesting physics at BES energies. In this document we discuss current proposed measurements, with estimations of the accuracy of the measurements given an assumed event count at each beam energy., Comment: 59 pages, 78 figures
Published: 2010

48. K*0 production in Cu+Cu and Au+Au collisions at \sqrt{s_NN} = 62.4 GeV and 200 GeV

Author: Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, Daniel, Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Baumgart, S., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., Bonner, B. E., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Catu, O., Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Clarke, R. F., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Das, D., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Mazumdar, M. R. Dutta, Efimov, L. G., Elhalhuli, E., Elnimr, M., Engelage, J., Eppley, G., Erazmus, B., Estienne, M., Eun, L., Evdokimov, O., Fachini, P., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Ganti, M. S., Garcia-Solis, E. J., Geromitsos, A., Geurts, F., Ghazikhanian, V., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., Guryn, W., Haag, B., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffman, A. M., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Jones, C. L., Jones, P. G., Joseph, J., Judd, E. G., Kabana, S., Kajimoto, K., Kang, K., Kapitan, J., Kauder, K., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Knospe, A. G., Kocoloski, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Kurnadi, P., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, C-H., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lin, G., Lindenbaum, S. J., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Nandi, B. K., Nattrass, C., Nayak, T. K., Nelson, J. M., Netrakanti, P. K., Ng, M. J., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Rose, A., Roy, C., Ruan, L., Sahoo, R., Sakai, S., Sakrejda, I., Sakuma, T., Salur, S., Sandweiss, J., Sangaline, E., Schambach, J., Scharenberg, R. P., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Sorensen, P., Sowinski, J., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Timoshenko, S., Tlusty, D., Tokarev, M., Trainor, T. A., Tram, V. N., Trentalange, S., Tribble, R. E., Tsai, O. D., Ulery, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Leeuwen, M., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Yue, Q., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, J., Zhong, C., Zhou, J., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract: We report on K*0 production at mid-rapidity in Au+Au and Cu+Cu collisions at \sqrt{s_{NN}} = 62.4 and 200 GeV collected by the Solenoid Tracker at RHIC (STAR) detector. The K*0 is reconstructed via the hadronic decays K*0 \to K+ pi- and \bar{K*0} \to K-pi+. Transverse momentum, pT, spectra are measured over a range of pT extending from 0.2 GeV/c to 5 GeV/c. The center of mass energy and system size dependence of the rapidity density, dN/dy, and the average transverse momentum, , are presented. The measured N(K*0)/N(K) and N(\phi)/N(K*0) ratios favor the dominance of re-scattering of decay daughters of K*0 over the hadronic regeneration for the K*0 production. In the intermediate pT region (2.0 < pT < 4.0 GeV/c), the elliptic flow parameter, v2, and the nuclear modification factor, RCP, agree with the expectations from the quark coalescence model of particle production., Comment: 14 pages and 13 figures
Published: 2010
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49. Higher Moments of Net-proton Multiplicity Distributions at RHIC

Author: Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Baumgart, S., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., Bonner, 3 B. E., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Catu, O., Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Clarke, R. F., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Das, D., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Mazumdar, M. R. Dutta, Efimov, L. G., Elhalhuli, E., Elnimr, M., Engelage, J., Eppley, G., Erazmus, B., Estienne, M., Eun, L., Evdokimov, O., Fachini, P., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Ganti, M. S., Garcia-Solis, E. J., Geromitsos, A., Geurts, F., Ghazikhanian, V., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., Gupta, N., Guryn, W., Haag, B., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffman, A. M., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Jones, C. L., Jones, P. G., Joseph, J., Judd, E. G., Kabana, S., Kajimoto, K., Kang, K., Kapitan, J., Kauder, K., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Klein, S. R., Knospe, A. G., Kocoloski, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Kurnadi, P., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, C-H., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lin, G., Lindenbaum, S. J., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Morozov, M. M. Mondal. B., Morozov, D. A., Munhoz, M. G., Nandi, B. K., Nattrass, C., Nayak, T. K., Nelson, J. M., Netrakanti, P. K., Ng, M. J., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Peitzmann, T., Perevoztchikov, V., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevsky, O. V., Romero, J. L., Rose, A., Roy, C., Ruan, L., Sahoo, R., Sakai, S., Sakrejda, I., Sakuma, T., Salur, S., Sandweiss, J., Sangaline, E., Schambach, J., Scharenberg, R. P., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Sorensen, P., Sowinski, J., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Timoshenko, S., Tlusty, D., Tokarev, M., Tram, V. N., Trentalange, S., Tribble, R. E., Tsai, O. D., Ulery, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Leeuwen, M., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Yue, Q., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, J., Zhong, C., Zhou, J., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Lattice, High Energy Physics - Phenomenology, Nuclear Theory
Abstract: We report the first measurements of the kurtosis (\kappa), skewness (S) and variance (\sigma^2) of net-proton multiplicity (N_p - N_pbar) distributions at midrapidity for Au+Au collisions at \sqrt(s_NN) = 19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (\mu_B) between 200 - 20 MeV. Our measurements of the products \kappa \sigma^2 and S \sigma, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the \sqrt(s_NN) dependence of \kappa \sigma^2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for \mu_B below 200 MeV., Comment: 6 pages and 4 figures. Version accepted for publication in Physical Review Letters
Published: 2010
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50. Azimuthal di-hadron correlations in d+Au and Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV from STAR

Author: STAR Collaboration, Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, Daniel, Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Baumgart, S., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., Bonner, B. E., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Catu, O., Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Clarke, R. F., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Das, D., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Mazumdar, M. R. Dutta, Efimov, L. G., Elhalhuli, E., Elnimr, M., Engelage, J., Eppley, G., Erazmus, B., Estienne, M., Eun, L., Evdokimov, O., Fachini, P., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Ganti, M. S., Garcia-Solis, E. J., Geromitsos, A., Geurts, F., Ghazikhanian, V., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., Gupta, N., Guryn, W., Haag, B., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffman, A. M., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Jones, C. L., Jones, P. G., Joseph, J., Judd, E. G., Kabana, S., Kajimoto, K., Kang, K., Kapitan, J., Kauder, K., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Klein, S. R., Knospe, A. G., Kocoloski, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Kurnadi, P., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, C-H., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lin, G., Lindenbaum, S. J., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Nandi, B. K., Nattrass, C., Nayak, T. K., Nelson, J. M., Netrakanti, P. K., Ng, M. J., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Peitzmann, T., Perevoztchikov, V., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Rose, A., Roy, C., Ruan, L., Sahoo, R., Sakai, S., Sakrejda, I., Sakuma, T., Salur, S., Sandweiss, J., Sangaline, E., Schambach, J., Scharenberg, R. P., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Sorensen, P., Sowinski, J., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Timoshenko, S., Tlusty, D., Tokarev, M., Trainor, T. A., Tram, V. N., Trentalange, S., Tribble, R. E., Tsai, O. D., Ulery, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Leeuwen, M., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Yue, Q., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, J., Zhong, C., Zhou, J., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.
Subjects: Nuclear Experiment
Abstract: Yields, correlation shapes, and mean transverse momenta \pt{} of charged particles associated with intermediate to high-\pt{} trigger particles ($2.5 < \pt < 10$ \GeVc) in d+Au and Au+Au collisions at $\snn=200$ GeV are presented. For associated particles at higher $\pt \gtrsim 2.5$ \GeVc, narrow correlation peaks are seen in d+Au and Au+Au, indicating that the main production mechanism is jet fragmentation. At lower associated particle $\pt < 2$ \GeVc, a large enhancement of the near- ($\dphi \sim 0$) and away-side ($\dphi \sim \pi$) associated yields is found, together with a strong broadening of the away-side azimuthal distributions in Au+Au collisions compared to d+Au measurements, suggesting that other particle production mechanisms play a role. This is further supported by the observed significant softening of the away-side associated particle yield distribution at $\dphi \sim \pi$ in central Au+Au collisions., Comment: 16 pages, 11 figures, updated after journal review
Published: 2010
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