Author: "De Leo, R" / Publication Year Range: Last 50 years - Searchworks@Jio Institute Digital Library Search Results

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1,065 results on '"De Leo, R"'

1. Deeply virtual Compton scattering off the neutron

Author: Benali, M., Desnault, C., Mazouz, M., Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., Defurne, M., de Jager, C. W., de Leo, R., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Huber, G. M., Hyde, C. E., Iqbal, S., Itard, F., Kang, Ho., Kang, Hy., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Pomatsalyuk, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatie, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zana, L., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Phenomenology, High Energy Physics - Experiment, Nuclear Experiment
Abstract: The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered off a nucleon by exchanging a virtual photon. Then, a highly-energetic real photon is emitted from one of the quarks inside the nucleon, which carries information on the quark's transverse position and longitudinal momentum. By measuring the cross-section of deeply virtual Compton scattering, Compton form factors related to the generalized parton distributions can be extracted. Here, we report the observation of unpolarized deeply virtual Compton scattering off a deuterium target. From the measured photon-electroproduction cross-sections, we have extracted the cross-section of a quasi-free neutron and a coherent deuteron. Due to the approximate isospin symmetry of quantum chromodynamics, we can determine the contributions from the different quark flavours to the helicity-conserved Compton form factors by combining our measurements with previous ones probing the proton's internal structure. These results advance our understanding of the description of the nucleon structure, which is important to solve the proton spin puzzle.
Published: 2021
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2. Measurement of the generalized spin polarizabilities of the neutron in the low $Q^2$ region

Author: Sulkosky, V., Peng, C., Chen, J. -P., Deur, A., Abrahamyan, S., Aniol, K. A., Armstrong, D. S., Averett, T., Bailey, S. L., Beck, A., Bertin, P., Butaru, F., Boeglin, W., Camsonne, A., Cates, G. D., Chang, C. C., Choi, Seonho, Chudakov, E., Coman, L., Cornejo, J. C, Craver, B., Cusanno, F., De Leo, R., de Jager, C. W., Denton, J. D., Dhamija, S., Feuerbach, R., Finn, J. M., Frullani, S., Fuoti, K., Gao, H., Garibaldi, F., Gayou, O., Gilman, R., Glamazdin, A., Glashausser, C., Gomez, J., Hansen, J. -O., Hayes, D., Hersman, B., Higinbotham, D. W., Holmstrom, T., Humensky, T. B., Hyde, C. E., Ibrahim, H., Iodice, M., Jiang, X., Kaufman, L. J., Kelleher, A., Keister, K. E., Kim, W., Kolarkar, A., Kolb, N., Korsch, W., Kramer, K., Kumbartzki, G., Lagamba, L., Laine, V., Laveissiere, G., Lerose, J. J., Lhuillier, D., Lindgren, R., Liyanage, N., Lu, H. -J., Ma, B., Margaziotis, D. J., Markowitz, P., McCormick, K., Meziane, M., Meziani, Z. -E., Michaels, R., Moffit, B., Monaghan, P., Nanda, S., Niedziela, J., Niskin, M., Pandolfi, R., Paschke, K. D., Potokar, M., Puckett, A., Punjabi, V. A., Qiang, Y., Ransome, R., Reitz, B., Roche, R., Saha, A., Shabetai, A., Sirca, S., Singh, J. T., Slifer, K., Snyder, R., Solvignon, P., Stringer, R., Subedi, R., Tobias, W. A., Ton, N., Ulmer, P. E., Urciuoli, G. M., Vacheret, A., Voutier, E., Wang, K., Wan, L., Wojtsekhowski, B., Woo, S., Yao, H., Yuan, J., Zhan, X., Zheng, X., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: Understanding the nucleon spin structure in the regime where the strong interaction becomes truly strong poses a challenge to both experiment and theory. At energy scales below the nucleon mass of about 1 GeV, the intense interaction among the quarks and gluons inside the nucleon makes them highly correlated. Their coherent behaviour causes the emergence of effective degrees of freedom, requiring the application of non-perturbative techniques, such as chiral effective field theory. Here, we present measurements of the neutron's generalized spin-polarizabilities that quantify the neutron's spin precession under electromagnetic fields at very low energy-momentum transfer squared down to 0.035 GeV$^2$. In this regime, chiral effective field theory calculations are expected to be applicable. Our data, however, show a strong discrepancy with these predictions, presenting a challenge to the current description of the neutron's spin properties., Comment: V1: initial version submitted to Nature Physics. V2: Published version. 16 pages, 7 figures. Additional material: 4 data tables (18 pages) V3: Typo corrected in author list. Paper content unchanged
Published: 2021
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3. Spectroscopy of $A=9$ hyperlithium by the $(e,e^{\prime}K^{+})$ reaction

Author: Gogami, T., Chen, C., Kawama, D., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Baturin, P., Badui, R., Boeglin, W., Bono, J., Brash, E., Carter, P., Chiba, A., Christy, E., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fujii, Y., Fujita, M., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Han, Y., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed. V., Jones, M., Kanda, H., Kaneta, M., Kato, S., Kawai, M., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Margaryan, A., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Meekins, D., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Qiu, X., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Tang, L., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Ya, L., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: Missing mass spectroscopy with the $(e,e^{\prime}K^{+})$ reaction was performed at Jefferson Laboratory's Hall C for the neutron rich $\Lambda$ hypernucleus $^{9}_{\Lambda}{\rm Li}$. The ground state energy was obtained to be $B_{\Lambda}^{\rm g.s.}=8.84\pm0.17^{\rm stat.}\pm0.15^{\rm sys.}~{\rm MeV}$ by using shell model calculations of a cross section ratio and an energy separation of the spin doublet states ($3/2^{+}_1$ and $5/2^{+}_1$). In addition, peaks that are considered to be states of [$^{8}{\rm Li}(3^{+})\otimes s_{\Lambda}=3/2^{+}_{2}, 1/2^{+}$] and [$^{8}{\rm Li}(1^{+})\otimes s_{\Lambda}=5/2^{+}_{2}, 7/2^{+}$] were observed at $E_{\Lambda}({\rm no.~2})=1.74\pm0.27^{\rm stat.}\pm0.11^{\rm sys.}~{\rm MeV}$ and $E_{\Lambda}({\rm no.~3})=3.30\pm0.24^{\rm stat.}\pm0.11^{\rm sys.}~{\rm MeV}$, respectively. The $E_{\Lambda}({\rm no.~3})$ is larger than shell model predictions by a few hundred keV, and the difference would indicate that a ${\rm ^{5}He}+t$ structure is more developed for the $3^{+}$ state than those for the $2^{+}$ and $1^{+}$ states in a core nucleus $^{8}{\rm Li}$ as a cluster model calculation suggests., Comment: 5 pages, 3 figures
Published: 2021
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4. Measurement of the Charge-Averaged Elastic Lepton-Proton Scattering Cross Section by the OLYMPUS Experiment

Author: Bernauer, J. C., Schmidt, A., Henderson, B. S., Ice, L. D., Khaneft, D., O'Connor, C., Russell, R., Akopov, N., Alarcon, R., Ates, O., Avetisyan, A., Beck, R., Belostotski, S., Bessuille, J., Brinker, F., Calarco, J. R., Carassiti, V., Cisbani, E., Ciullo, G., Contalbrigo, M., De Leo, R., Diefenbach, J., Donnelly, T. W., Dow, K., Elbakian, G., Eversheim, P. D., Frullani, S., Funke, Ch., Gavrilov, G., Gläser, B., Görrissen, N., Hasell, D. K., Hauschildt, J., Hoffmeister, Ph., Holler, Y., Ihloff, E., Izotov, A., Kaiser, R., Karyan, G., Kelsey, J., Kiselev, A., Klassen, P., Krivshich, A., Kohl, M., Lehmann, I., Lenisa, P., Lenz, D., Lumsden, S., Ma, Y., Maas, F., Marukyan, H., Miklukho, O., Milner, R. G., Movsisyan, A., Murray, M., Naryshkin, Y., Benito, R. Perez, Perrino, R., Redwine, R. P., Piñeiro, D. Rodríguez, Rosner, G., Schneekloth, U., Seitz, B., Statera, M., Thiel, A., Vardanyan, H., Veretennikov, D., Vidal, C., Winnebeck, A., and Yeganov, V.
Subjects: Nuclear Experiment
Abstract: We report the first measurement of the average of the electron-proton and positron-proton elastic scattering cross sections. This lepton charge-averaged cross section is insensitive to the leading effects of hard two-photon exchange, giving more robust access to the proton's electromagnetic form factors. The cross section was extracted from data taken by the OLYMPUS experiment at DESY, in which alternating stored electron and positron beams were scattered from a windowless gaseous hydrogen target. Elastic scattering events were identified from the coincident detection of the scattered lepton and recoil proton in a large-acceptance toroidal spectrometer. The luminosity was determined from the rates of M{\o}ller, Bhabha and elastic scattering in forward electromagnetic calorimeters. The data provide some selectivity between existing form factor global fits and will provide valuable constraints to future fits., Comment: 6 pages, 3 figures, submitted to PRL
Published: 2020
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5. Azimuthal single- and double-spin asymmetries in semi-inclusive deep-inelastic lepton scattering by transversely polarized protons

Author: HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Bacchetta, A., Belostotski, S., Bryzgalov, V., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Elbakian, G., Ellinghaus, F., Fantoni, A., Felawka, L., Gavrilov, G., Gharibyan, V., Holler, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Kinney, E., Kisselev, A., Kozlov, V., Kravchenko, P., Lagamba, L., Lapikás, L., Lenisa, P., Lorenzon, W., Manaenkov, S. I., Marianski, B., Marukyan, H., Miyachi, Y., Movsisyan, A., Muccifora, V., Naryshkin, Y., Nass, A., Nazaryan, G., Nowak, W. -D., Pappalardo, L. L., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Statera, M., Terkulov, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vilardi, I., Yaschenko, S., Zeiler, D., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: A comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction of pions, charged kaons, protons, and antiprotons from transversely polarized protons is presented. These asymmetries include the previously published HERMES results on Collins and Sivers asymmetries, the analysis of which has been extended to include protons and antiprotons and also to an extraction in a three-dimensional kinematic binning and enlarged phase space. They are complemented by corresponding results for the remaining four single-spin and four double-spin asymmetries allowed in the one-photon-exchange approximation of the semi-inclusive deep-inelastic scattering process for target-polarization orientation perpendicular to the direction of the incoming lepton beam. Among those results, significant non-vanishing $\cos{\phi-\phi_S}$ modulations provide evidence for a sizable worm-gear (II) distribution, $g_{1T}$. Most of the other modulations are found to be consistent with zero with the notable exception of large $\sin{\phi_S}$ modulations for charged pions and positive kaons.
Published: 2020

6. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab -- 2018 update to PR12-16-001

Author: Battaglieri, M., Bersani, A., Bracco, G., Caiffi, B., Celentano, A., De Vita, R., Marsicano, L., Musico, P., Panza, F., Ripani, M., Santopinto, E., Taiuti, M., Bellini, V., Bondi', M., Castorina, P., De Napoli, M., Italiano, A., Kuznetzov, V., Leonora, E., Mammoliti, F., Randazzo, N., Re, L., Russo, G., Russo, M., Shahinyan, A., Sperduto, M., Spinali, S., Sutera, C., Tortorici, F., Baltzell, N., Dalton, M., Freyberger, A., Girod, F. -X., Kharashvili, G., Kubarovsky, V., Pasyuk, E., Smith, E. S., Stepanyan, S., Szumilla-Vance, H., Ungaro, M., Whitlatch, T., Izaguirre, E., Krnjaic, G., Ehle, I., Snowden-Ifft, D., Loomba, D., Carpinelli, M., D'Urso, D., Gabrieli, A., Maccioni, G., Sant, M., Sipala, V., Ameli, F., Cisbani, E., De Persio, F., Del Dotto, A., Garibaldi, F., Meddi, F., Nicolau, C. A., Urciuoli, G. M., Chiarusi, T., Manzali, M., Pellegrino, C., Schuster, P., Toro, N., Essig, R., Wood, M. H., Holtrop., M., Paremuzyan, R., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Nappi, E., Perrino, R., Balossino, I., Barion, L., Ciullo, G., Contalbrigo, M., Drago, A., Lenisa, P., Movsisyan, A., Pappalardo, L., Spizzo, F., Turisini, M., Hasch, D., Lucherini, V., Mirazita, M., Pisano, S., Rossi, P., Tomassini, S., Simi, G., D'Angelo, A., Lanza, L., Rizzo, A., Filippi, A., Genovese, M., Kunkel, M., Bashkanov, M., Murphy, A., Smith, G., Watts, D., Zachariou, N., Zana, L., Glazier, D., Ireland, D., McKinnon, B., Sokhan, D., Colaneri, L., Pereira, S. Anefalos, Afanasev, A., Briscoe, B., Strakovsky, I., Kalantarians, N., Weinstein, L., Adhikari, K. P., Dunne, J. A., Dutta, D., Fassi, L. El, Ye, L., Hicks, K., Cole, P., Dobbs, S., Fanelli, C., and Mohanmurthy, P.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: This document complements and completes what was submitted last year to PAC45 as an update to the proposal PR12-16-001 "Dark matter search in a Beam-Dump eXperiment (BDX)" at Jefferson Lab submitted to JLab-PAC44 in 2016. Following the suggestions contained in the PAC45 report, in coordination with the lab, we ran a test to assess the beam-related backgrounds and validate the simulation framework used to design the BDX experiment. Using a common Monte Carlo framework for the test and the proposed experiment, we optimized the selection cuts to maximize the reach considering simultaneously the signal, cosmic-ray background (assessed in Catania test with BDX-Proto) and beam-related backgrounds (irreducible NC and CC neutrino interactions as determined by simulation). Our results confirmed what was presented in the original proposal: with 285 days of a parasitic run at 65 $\mu$A (corresponding to $10^{22}$ EOT) the BDX experiment will lower the exclusion limits in the case of no signal by one to two orders of magnitude in the parameter space of dark-matter coupling versus mass.
Published: 2019

7. Measurement of the 3He Spin-Structure Functions and of Neutron (3He) Spin-Dependent Sum Rules at 0.035<Q^2<0.24 GeV^2

Author: Sulkosky, V., Singh, J. T., Peng, C., Chen, J. -P., Deur, A., Abrahamyan, S., Aniol, K. A., Armstrong, D. S., Averett, T., Bailey, S. L., Beck, A., Bertin, P., Butaru, F., Boeglin, W., Camsonne, A., Cates, G. D., Chang, C. C., Choi, Seonho, Chudakov, E., Coman, L., Cornejo, J. C, Craver, B., Cusanno, F., De Leo, R., de Jager, C. W., Denton, J. D., Dhamija, S., Feuerbach, R., Finn, J. M., Frullani, S., Fuoti, K., Gao, H., Garibaldi, F., Gayou, O., Gilman, R., Glamazdin, A., Glashausser, C., Gomez, J., Hansen, J. -O., Hayes, D., Hersman, B., Higinbotham, D. W., Holmstrom, T., Humensky, T. B., Hyde, C. E., Ibrahim, H., Iodice, M., Jiang, X., Kaufman, L. J., Kelleher, A., Keister, K. E., Kim, W., Kolarkar, A., Kolb, N., Korsch, W., Kramer, K., Kumbartzki, G., Lagamba, L., Laine, V., Laveissiere, G., Lerose, J. J., Lhuillier, D., Lindgren, R., Liyanage, N., Lu, H. -J., Ma, B., Margaziotis, D. J., Markowitz, P., McCormick, K., Meziane, M., Meziani, Z. -E., Michaels, R., Moffit, B., Monaghan, P., Nanda, S., Niedziela, J., Niskin, M., Pandolfi, R., Paschke, K. D., Potokar, M., Puckett, A., Punjabi, V. A., Qiang, Y., Ransome, R., Reitz, B., Roche, R., Saha, A., Shabetai, A., Sirca, S., Slifer, K., Snyder, R., Solvignon, P., Stringer, R., Subedi, R., Tobias, W. A., Ton, N., Ulmer, P. E., Urciuoli, G. M., Vacheret, A., Voutier, E., Wang, K., Wan, L., Wojtsekhowski, B., Woo, S., Yao, H., Yuan, J., Zhan, X., Zheng, X., and Zhu, L.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The spin-structure functions $g_1$ and $g_2$, and the spin-dependent partial cross-section $\sigma_\mathrm{TT}$ have been extracted from the polarized cross-sections differences, $\Delta \sigma_{\parallel}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ and $\Delta \sigma_{\perp}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ measured for the $\vec{^\textrm{3}\textrm{He}}(\vec{\textrm{e}},\textrm{e}')\textrm{X}$ reaction, in the E97-110 experiment at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404 GeV were scattered at angles of 6$^{\circ}$ and 9$^{\circ}$ from a longitudinally or transversely polarized $^{3}$He target. The data cover the kinematic regions of the quasi-elastic, resonance production and beyond. From the extracted spin-structure functions, the first moments $\overline{\Gamma_1}\hspace{-0.06cm}\left(Q^{2}\right)$, $\Gamma_2\hspace{-0.06cm}\left(Q^{2}\right)$ and $I_{\mathrm{TT}}\hspace{-0.06cm}\left(Q^{2}\right)$ are evaluated with high precision for the neutron in the $Q^2$ range from 0.035 to 0.24~GeV$^{2}$. The comparison of the data and the chiral effective field theory predictions reveals the importance of proper treatment of the $\Delta$ degree of freedom for spin observables., Comment: 7 pages, 5 figures, 3 tables. Version published in Phys. Lett. B
Published: 2019
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8. Measurement of the single-spin asymmetry $A_y^0$ in quasi-elastic $^3$He$^\uparrow$($e,e'n$) scattering at $0.4 < Q^2 < 1.0$ GeV$/c^2$

Author: Long, E., Zhang, Y. W., Mihoviloviv, M., Jin, G., Sulkosky, V., Kelleher, A., Anderson, B., Higinbotham, D. W., Sirca, S., Allada, K., Annand, J. R. M., Averett, T., Bertozzi, W., Boeglin, W., Bradshaw, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chudakov, E., De Leo, R., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Frullani, S., Garibaldi, F., Gao, H., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Hansen, J. -O., Holmstrom, T., Huang, J., Ibrahim, H., de Jager, C. W., Jensen, E., Jiang, X., Jones, M., Kang, H., Katich, J., Khanal, H. P., King, P. M., Korsch, W., LeRose, J., Lindgren, R., Lu, H. -J., Luo, W., Markowitz, P., Meziane, M., Michaels, R., Moffit, B., Monaghan, P., Muangma, N., Nanda, S., Norum, B. E., Pan, K., Parno, D., Piasetzky, E., Posik, M., Punjabi, V., Puckett, A. J. R., Qian, X., Qiang, Y., Qui, X., Riordan, S., Saha, A., Sawatzky, B., Shabestari, M., Shahinyan, A., Shoenrock, B., John, J. St., Subedi, R., Tobias, W. A., Tireman, W., Urciuoli, G. M., Wang, D., Wang, K., Wang, Y., Watson, J., Wojtsekhowski, B., Ye, Z., Zhan, X., Zhang, Y., Zheng, X., Zhao, B., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: Due to the lack of free neutron targets, studies of the structure of the neutron are typically made by scattering electrons from either $^2$H or $^3$He targets. In order to extract useful neutron information from a $^3$He target, one must understand how the neutron in a $^3$He system differs from a free neutron by taking into account nuclear effects such as final state interactions and meson exchange currents. The target single spin asymmetry $A_y^0$ is an ideal probe of such effects, as any deviation from zero indicates effects beyond plane wave impulse approximation. New measurements of the target single spin asymmetry $A_y^0$ at $Q^2$ of 0.46 and 0.96 (GeV/$c)^2$ were made at Jefferson Lab using the quasi-elastic $^3\mathrm{He}^{\uparrow}(e,e'n)$ reaction. Our measured asymmetry decreases rapidly, from $>20\%$ at $Q^2=0.46$ (GeV/$c)^2$ to nearly zero at $Q^2=0.96$ (GeV$/c)^2$, demonstrating the fall-off of the reaction mechanism effects as $Q^2$ increases. We also observed a small $\epsilon$-dependent increase in $A_y^0$ compared to previous measurements, particularly at moderate $Q^2$. This indicates that upcoming high $Q^2$ measurements from the Jefferson Lab 12 GeV program can cleanly probe neutron structure from polarized $^3$He using plane wave impulse approximation., Comment: 6 pages, 5 figures
Published: 2019
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9. Longitudinal double-spin asymmetries in semi-inclusive deep-inelastic scattering of electrons and positrons by protons and deuterons

Author: HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Belostotski, S., Blok, H. P., Borissov, A., Bryzgalov, V., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Elbakian, G., Ellinghaus, F., Fantoni, A., Felawka, L., Frullani, S., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Hasch, D., Holler, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lorenzon, W., Ma, B. -Q., Mahon, D., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Miyachi, Y., Movsisyan, A., Muccifora, V., Mussgiller, A., Naryshkin, Y., Nass, A., Nazaryan, G., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schnell, G., Seitz, B., Shibata, T. -A., Statera, M., Steffens, E., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., van der Nat, P. B., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: A comprehensive collection of results on longitudinal double-spin asymmetries is presented for charged pions and kaons produced in semi-inclusive deep-inelastic scattering of electrons and positrons on the proton and deuteron, based on the full HERMES data set. The dependence of the asymmetries on hadron transverse momentum and azimuthal angle extends the sensitivity to the flavor structure of the nucleon beyond the distribution functions accessible in the collinear framework. No strong dependence on those variables is observed. In addition, the hadron charge-difference asymmetry is presented, which under certain model assumptions provides access to the helicity distributions of valence quarks.
Published: 2018
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10. High-resolution hypernuclear spectroscopy at Jefferson Lab, Hall A

Author: Jefferson Lab Hall A Collaboration, Garibaldi, F., Acha, A., Ambrozewicz, P., Aniol, K. A., Beturin, P., Benaoum, H., Benesch, J., Bertin, P. Y., Blomqvist, K. I., Boeglin, W. U., Breuer, H., Brindza, P., Bydzovsky, P., Camsonne, A., Chang, C. C., Chen, J. -P., Choi, Seonho, Chudakov, E. A., Cisbani, E., Colilli, S., Coman, L., Cusanno, F., Craver, B. J., De Cataldo, G., de Jager, C. W., De Leo, R., Deur, A. P., Ferdi, C., Feuerbach, R. J., Folts, E., Frullani, S., Gayou, O., Giuliani, F., Gomez, J., Gricia, M., Hansen, J. O., Hayes, D., Higinbotham, D. W., Holmstrom, T. K., Hyde, C. E., Ibrahim, H. F., Iodice, M., Jiang, X., Kaufman, L. J., Kino, K., Kross, B., Lagamba, L., LeRose, J. J., Lindgren, R. A., Lucentini, M., Margaziotis, D. J., Markowitz, P., Marrone, S., Meekins, D. G., Meziani, Z. E., McCormick, K., Michaels, R. W., Millener, D. J., Miyoshi, T., Moffit, B., Monaghan, P. A., Moteabbed, M., Camacho, C. Munoz, Nanda, S., Nappi, E., Nelyubin, V. V., Norum, B. E., Okasyasu, Y., Paschke, K. D., Perdrisat, C. F., Piasetzky, E., Punjabi, V. A., Qiang, Y., Raue, B., Reimer, P. E., Reinhold, J., Reitz, B., Roche, R. E., Rodriguez, V. M., Saha, A., Santavenere, F., Sarty, A. J., Segal, J., Shahinyan, A., Singh, J., Sirca, S., Snyder, R., Solvignon, P. H., Sotona, M., Subedi, R., Sulkosky, V. A., Suzuki, T., Ueno, H., Ulmer, P. E., Urciuoli, G. M., Voutier, E., Wojtsekhowski, B. B., Zheng, X., and Zorn, C.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: The experiment E94-107 in Hall A at Jefferson Lab started a systematic study of high resolution hypernuclear spectroscopy in the 0p-shell region of nuclei such as the hypernuclei produced in electroproduction on 9Be, 12C and 16O targets. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring-imaging Cherenkov detector were added to the Hall A standard equipment. The high-quality beam, the good spectrometers and the new experimental devices allowed us to obtain very good results. For the first time, measurable strength with sub-MeV energy resolution was observed for the core-excited states of Lambda 12B. A high-quality Lambda 16N hypernuclear spectrum was likewise obtained. A first measurement of the Lambda binding energy for Lambda 16N, calibrated against the elementary reaction on hydrogen, was obtained with high precision, 13.76 +/- 0.16 MeV. Similarly, the first Lambda 9Li hypernuclear spectrum shows general agreement with theory (distorted-wave impulse approximation with the SLA and BS3 electroproduction models and shell-model wave functions). Some disagreement exists with respect to the relative strength of the states making up the first multiplet. A Lambda separation energy of 8.36 MeV was obtained, in agreement with previous results. It has been shown that the electroproduction of hypernuclei can provide information complementary to that obtained with hadronic probes and the gamma-ray spectroscopy technique., Comment: 27 pages, 18 figures, submitted to Physical Review C
Published: 2018
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11. Measurement of double-polarization asymmetries in the quasi-elastic $^3\vec{\mathrm{He}}(\vec{\mathrm{e}},\mathrm{e}'\mathrm{p})$ process

Author: Mihovilovič, M., Jin, G., Long, E., Zhang, Y. -W., Allada, K., Anderson, B., Annand, J. R. M., Averett, T., Bertozzi, W., Boeglin, W., Bradshaw, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. P., Chudakov, E., De Leo, R., Deng, X., Deltuva, A., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Frullani, S., Garibaldi, F., Gao, H., Gilad, S., Gilman, R., Glamazdin, O., Golak, J., Golge, S., Gomez, J., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Ibrahim, H., de Jager, C. W., Jensen, E., Jiang, X., Jones, M., Kamada, H., Kang, H., Katich, J., Khanal, H. P., Kievsky, A., King, P., Korsch, W., LeRose, J., Lindgren, R., Lu, H. -J., Luo, W., Marcucci, L. E., Markowitz, P., Meziane, M., Michaels, R., Moffit, B., Monaghan, P., Muangma, N., Nanda, S., Norum, B. E., Pan, K., Parno, D. S., Piasetzky, E., Posik, M., Punjabi, V., Puckett, A. J. R., Qian, X., Qiang, Y., Qui, X., Riordan, S., Saha, A., Sauer, P. U., Sawatzky, B., Schiavilla, R., Schoenrock, B., Shabestari, M., Shahinyan, A., Širca, S., Skibiński, R., John, J. St., Subedi, R., Sulkosky, V., Tireman, W., Tobias, W. A., Topolnicki, K., Urciuoli, G. M., Viviani, M., Wang, D., Wang, K., Wang, Y., Watson, J., Wojtsekhowski, B., Witała, H., Ye, Z., Zhan, X., Zhang, Y., Zheng, X., Zhao, B., Zhu, L., and Collaboration, The Jefferson Lab Hall A
Subjects: Nuclear Experiment
Abstract: We report on a precise measurement of double-polarization asymmetries in electron-induced breakup of $^3\mathrm{He}$ proceeding to $\mathrm{pd}$ and $\mathrm{ppn}$ final states, performed in quasi-elastic kinematics at $Q^2 = 0.25\,(\mathrm{GeV}/c)^2$ for missing momenta up to $250\,\mathrm{MeV}/c$. These observables represent highly sensitive tools to investigate the electromagnetic and spin structure of $^3\mathrm{He}$ and the relative importance of two- and three-body effects involved in the breakup reaction dynamics. The measured asymmetries cannot be satisfactorily reproduced by state-of-the-art calculations of $^3\mathrm{He}$ unless their three-body segment is adjusted, indicating that the spin-dependent part of the nuclear interaction governing the three-body breakup process is much smaller than previously thought., Comment: 5 pages, 3 figures, submitted to Phys. Rev. Lett
Published: 2018
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12. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab: an update on PR12-16-001

Author: Battaglieri, M., Bersani, A., Bracco, G., Caiffi, B., Celentano, A., De Vita, R., Marsicano, L., Musico, P., Osipenko, M., Panza, F., Ripani, M., Santopinto, E., Taiuti, M., Bellini, V., Bondi', M., Castorina, P., De Napoli, M., Italiano, A., Kuznetzov, V., Leonora, E., Mammoliti, F., Randazzo, N., Re, L., Russo, G., Russo, M., Shahinyan, A., Sperduto, M., Spinali, S., Sutera, C., Tortorici, F., Baltzell, N., Dalton, M., Freyberger, A., Girod, F. -X., Kharashvili, G., Kubarovsky, V., Pasyuk, E., Smith, E. S., Stepanyan, S., Ungaro, M., Whitlatch, T., Izaguirre, E., Krnjaic, G., Snowden-Ifft, D., Loomba, D., Carpinelli, M., D'Urso, D., Gabrieli, A., Maccioni, G., Sant, M., Sipala, V., Ameli, F., Cisbani, E., De Persio, F., Del Dotto, A., Garibaldi, F., Meddi, F., Nicolau, C. A., Urciuoli, G. M., Chiarusi, T., Manzali, M., Pellegrino, C., Schuster, P., Toro, N., Essig, R., Wood, M. H., Paremuzyan, M. Holtrop. R., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Nappi, E., Perrino, R., Balossino, I., Barion, L., Ciullo, G., Contalbrigo, M., Drago, A., Lenisa, P., Movsisyan, A., Pappalardo, L., Spizzo, F., Turisini, M., Hasch, D., Lucherini, V., Mirazita, M., Pisano, S., Rossi, P., Tomassini, S., Simi, G., D'Angelo, A., Lanza, L., Rizzo, A., Schaerf, C., Zonta, I., Filippi, A., Genovese, M., Fegan, S., Kunkel, M., Bashkanov, M., Murphy, A., Smith, G., Watts, D., Zachariou, N., Zana, L., Glazier, D., Ireland, D., McKinnon, B., Sokhan, D., Colaneri, L., Pereira, S. Anefalos, Afanasev, A., Briscoe, B., Strakovsky, I., Kalantarians, N., Weinstein, L., Adhikari, K. P., Dunne, J. A., Dutta, D., Fassi, L. El, Ye, L., Hicks, K., Cole, P., Dobbs, S., Fanelli, C., and Murthy, P. T. M.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: This document is an update to the proposal PR12-16-001 Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab submitted to JLab-PAC44 in 2016 reporting progress in addressing questions raised regarding the beam-on backgrounds. The concerns are addressed by adopting a new simulation tool, FLUKA, and planning measurements of muon fluxes from the dump with its existing shielding around the dump. First, we have implemented the detailed BDX experimental geometry into a FLUKA simulation, in consultation with experts from the JLab Radiation Control Group. The FLUKA simulation has been compared directly to our GEANT4 simulations and shown to agree in regions of validity. The FLUKA interaction package, with a tuned set of biasing weights, is naturally able to generate reliable particle distributions with very small probabilities and therefore predict rates at the detector location beyond the planned shielding around the beam dump. Second, we have developed a plan to conduct measurements of the muon ux from the Hall-A dump in its current configuration to validate our simulations., Comment: Document submitted to JLab PAC 45
Published: 2017

13. Extraction of the Neutron Electric Form Factor from Measurements of Inclusive Double Spin Asymmetries

Author: Sulkosky, V., Jin, G., Long, E., Zhang, Y. W., Mihovilovic, M., Kelleher, A., Anderson, B., Higinbotham, D. W., Sirca, S., Allada, K., Annand, J. R. M., Averett, T., Bertozzi, W., Boeglin, W., Bradshaw, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chudakov, E., De Leo, R., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Frullani, S., Garibaldi, F., Gao, H., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Hansen, J. -O., Holmstrom, T., Huang, J., Ibrahim, H., de Jager, C. W., Jensen, E., Jiang, X., Jones, M., Kang, H., Katich, J., Khanal, H. P., King, P., Korsch, W., LeRose, J., Lindgren, R., Lu, H. J., Luo, W., Markowitz, P., Meekins, D., Meziane, M., Michaels, R., Moffit, B., Monaghan, P., Muangma, N., Nanda, S., Norum, B. E., Pan, K., Parno, D., Piasetzky, E., Posik, M., Punjabi, V., Puckett, A. J. R., Qian, X., Qiang, Y., Qui, X., Riordan, S., Saha, A., Sawatzky, B., Shabestari, M., Shahinyan, A., Shoenrock, B., John, J. St., Subedi, R., Tobias, W. A., Tireman, W., Urciuoli, G. M., Wang, D., Wang, K., Wang, Y., Watson, J., Wojtsekhowski, B., Ye, Z., Zhan, X., Zhang, Y., Zheng, X., Zhao, B., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: $[Background]$ Measurements of the neutron charge form factor, $G^n_E$, are challenging due to the fact that the neutron has no net charge. In addition, measurements of the neutron form factors must use nuclear targets which require accurately accounting for nuclear effects. Extracting $G^n_E$ with different targets and techniques provides an important test of our handling of these effects. $[Purpose]$ The goal of the measurement was to use an inclusive asymmetry measurement technique to extract the neutron charge form factor at a four-momentum transfer of $1~(\rm{GeV/c})^2$. This technique has very different systematic uncertainties than traditional exclusive measurements and thus serves as an independent check of whether nuclear effects have been taken into account correctly. $[Method]$ The inclusive quasi-elastic reaction $^3\overrightarrow{\rm{He}}(\overrightarrow{e},e')$ was measured at Jefferson Lab. The neutron electric form factor, $G_E^n$, was extracted at $Q^2 = 0.98~(\rm{GeV/c})^2$ from ratios of electron-polarization asymmetries measured for two orthogonal target spin orientations. This $Q^2$ is high enough that the sensitivity to $G_E^n$ is not overwhelmed by the neutron magnetic contribution, and yet low enough that explicit neutron detection is not required to suppress pion production. $[Results]$ The neutron electric form factor, $G_E^n$, was determined to be $0.0414\pm0.0077\;{(stat)}\pm0.0022\;{(syst)}$; providing the first high precision inclusive extraction of the neutron's charge form factor. $[Conclusions]$ The use of the inclusive quasi-elastic $^3\overrightarrow{\rm{He}}(\overrightarrow{e},e')$ with a four-momentum transfer near $1~(\rm{GeV/c})^2$ has been used to provide a unique measurement of $G^n_E$. This new result provides a systematically independent validation of the exclusive extraction technique results., Comment: 7 pages, 2 figures, 2 tables
Published: 2017
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14. A Glimpse of Gluons through Deeply Virtual Compton Scattering on the Proton

Author: Defurne, M., Jiménez-Argüello, A. Martì, Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Hyde, C. E., Iqbal, S., Itard, F., Kang, H., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Mazouz, M., Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatié, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: The proton is composed of quarks and gluons, bound by the most elusive mechanism of strong interaction called confinement. In this work, the dynamics of quarks and gluons are investigated using deeply virtual Compton scattering (DVCS): produced by a multi-GeV electron, a highly virtual photon scatters off the proton which subsequently radiates a high energy photon. Similarly to holography, measuring not only the magnitude but also the phase of the DVCS amplitude allows to perform 3D images of the internal structure of the proton. The phase is made accessible through the quantum-mechanical interference of DVCS with the Bethe-Heitler (BH) process, in which the final photon is emitted by the electron rather than the proton. We report herein the first full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the high energy regime where the scattering process is expected to occur off a single quark in the proton, these accurate measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.
Published: 2017
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15. Rosenbluth separation of the $\pi^0$ Electroproduction Cross Section off the Neutron

Author: Mazouz, M., Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., Defurne, M., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Huber, G. M., Hyde, C. E., Iqbal, S., Itard, F., Kang, Ho., Kang, Hy., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jiménez-Argüello, A. Martí, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Muñoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatié, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zana, L., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report the first longitudinal/transverse separation of the deeply virtual exclusive $\pi^0$ electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions $d\sigma_L/dt$, $d\sigma_T/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{TT}/dt$ are extracted as a function of the momentum transfer to the recoil system at $Q^2$=1.75 GeV$^2$ and $x_B$=0.36. The $ed \to ed\pi^0$ cross sections are found compatible with the small values expected from theoretical models. The $en \to en\pi^0$ cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity GPDs of the nucleon. By combining these results with previous measurements of $\pi^0$ electroproduction off the proton, we present a flavor decomposition of the $u$ and $d$ quark contributions to the cross section., Comment: 6 pages, 6 figures, Submitted to Phys. Rev. Lett
Published: 2017
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16. Ratios of helicity amplitudes for exclusive $\rho^0$ electroproduction on transversely polarized protons

Author: The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Belostotski, S., Blok, H. P., Borissov, A., Bryzgalov, V., Capitani, G. P., Ciullo, G., Contalbrigo, M., Deconinck, W., De Leo, R., De Sanctis, E., Düren, M., Elbakian, G., Ellinghaus, F., Felawka, L., Frullani, S., Garibaldi, F., Gavrilov, G., Gharibyan, V., Goloskokov, S. V., Holler, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Kroll, P., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Lorenzon, W., Manaenkov, S. I., Marianski, B., Marukyan, H., Miyachi, Y., Movsisyan, A., Muccifora, V., Nass, A., Nowak, W. -D., Pappalardo, L. L., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Ryckbosch, D., Salomatin, Y., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Statera, M., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Yaschenko, S., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Exclusive $\rho^0$-meson electroproduction is studied by the HERMES experiment, using the 27.6 GeV longitudinally polarized electron/positron beam of HERA and a transversely polarized hydrogen target, in the kinematic region 1.0 GeV$^2$
Published: 2017
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17. Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering: Determined by the OLYMPUS Experiment

Author: Henderson, B. S., Ice, L. D., Khaneft, D., O'Connor, C., Russell, R., Schmidt, A., Bernauer, J. C., Kohl, M., Akopov, N., Alarcon, R., Ates, O., Avetisyan, A., Beck, R., Belostotski, S., Bessuille, J., Brinker, F., Calarco, J. R., Carassiti, V., Cisbani, E., Ciullo, G., Contalbrigo, M., De Leo, R., Diefenbach, J., Donnelly, T. W., Dow, K., Elbakian, G., Eversheim, P. D., Frullani, S., Funke, Ch., Gavrilov, G., Gläser, B., Görrissen, N., Hasell, D. K., Hauschildt, J., Hoffmeister, Ph., Holler, Y., Ihloff, E., Izotov, A., Kaiser, R., Karyan, G., Kelsey, J., Kiselev, A., Klassen, P., Krivshich, A., Lehmann, I., Lenisa, P., Lenz, D., Lumsden, S., Ma, Y., Maas, F., Marukyan, H., Miklukho, O., Milner, R. G., Movsisyan, A., Murray, M., Naryshkin, Y., Benito, R. Perez, Perrino, R., Redwine, R. P., Piñeiro, D. Rodríguez, Rosner, G., Schneekloth, U., Seitz, B., Statera, M., Thiel, A., Vardanyan, H., Veretennikov, D., Vidal, C., Winnebeck, A., and Yeganov, V.
Subjects: Nuclear Experiment
Abstract: The OLYMPUS collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, $R_{2\gamma}$, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01~GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of $\approx 20\degree$ to $80\degree$. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved GEM and MWPC detectors at $12\degree$, as well as symmetric M{\o}ller/Bhabha calorimeters at $1.29\degree$. A total integrated luminosity of 4.5~fb$^{-1}$ was collected. In the extraction of $R_{2\gamma}$, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of $R_{2\gamma}$, presented here for a wide range of virtual photon polarization $0.456<\epsilon<0.978$, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data., Comment: 5 pages, 3 figures, 2 tables
Published: 2016
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18. First measurement of unpolarized SIDIS cross section and cross section ratios from a $^3$He target

Author: Yan, X., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liu, T., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Munoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Sirca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, W. A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Wang, Y., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zhao, Y. X., Zheng, X., Zhu, L., Zhu, X., and Zong, X.
Subjects: Nuclear Experiment
Abstract: The unpolarized semi-inclusive deep-inelastic scattering (SIDIS) differential cross sections in $^3$He($e,e^{\prime}\pi^{\pm}$)$X$ have been measured for the first time in Jefferson Lab experiment E06-010 performed with a $5.9\,$GeV $e^-$ beam on a $^3$He target. The experiment focuses on the valence quark region, covering a kinematic range $0.12 < x_{bj} < 0.45$, $1 < Q^2 < 4 \, \textrm{(GeV/c)}^2$, $0.45 < z_{h} < 0.65$, and $0.05 < P_t < 0.55 \, \textrm{GeV/c}$. The extracted SIDIS differential cross sections of $\pi^{\pm}$ production are compared with existing phenomenological models while the $^3$He nucleus approximated as two protons and one neutron in a plane wave picture, in multi-dimensional bins. Within the experimental uncertainties, the azimuthal modulations of the cross sections are found to be consistent with zero.
Published: 2016
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19. Rosenbluth separation of the $\pi^0$ electroproduction cross section

Author: Defurne, M., Mazouz, M., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Hyde, C. E., Iqbal, S., Itard, F., Kang, H., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabati, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zafar, A., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We present deeply virtual $\pi^0$ electroproduction cross-section measurements at $x_B$=0.36 and three different $Q^2$--values ranging from 1.5 to 2 GeV$^2$, obtained from experiment E07-007 that ran in the Hall A at Jefferson Lab. The Rosenbluth technique was used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component, and thus is far from the asymptotic limit predicted by perturbative Quantum Chromodynamics. An indication of a non-zero longitudinal contribution is provided by the interference term $\sigma_{LT}$ also measured. Results are compared with several models based on the leading twist approach of Generalized Parton Distributions (GPDs). In particular, a fair agreement is obtained with models where the scattering amplitude is described by a convolution of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. Therefore, neutral pion electroproduction may offer the exciting possibility of accessing transversity GPDs through experiment., Comment: Submitted to Physical Review Letters
Published: 2016
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20. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

Author: Battaglieri, M., Bersani, A., Caiffi, B., Celentano, A., De Vita, R., Fanchini, E., Marsicano, L., Musico, P., Osipenko, M., Panza, F., Ripani, M., Santopinto, E., Taiuti, M., Bellini, V., Bondí, M., De Napoli, M., Mammoliti, F., Leonora, E., Randazzo, N., Russo, G., Sperduto, M., Sutera, C., Tortorici, F., Baltzell, N., Dalton, M., Freyberger, A., Girod, F. X., Kubarovsky, V., Pasyuk, E., Smith, E. S., Stepanyan, S., Ungaro, M., Whitlatch, T., Izaguirre, E., Krnjaic, G., Snowden-Ifft, D., Loomba, D., Carpinelli, M., Sipala, V., Schuster, P., Toro, N., Essig, R., Wood, M. H., Holtrop, M., Paremuzyan, R., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Nappi, E., Perrino, R., Balossino, I., Barion, L., Ciullo, G., Contalbrigo, M., Lenisa, P., Movsisyan, A., Spizzo, F., Turisini, M., De Persio, F., Cisbani, E., Garibaldi, F., Meddi, F., Urciuoli, G. M., Hasch, D., Lucherini, V., Mirazita, M., Pisano, S., Simi, G., D'Angelo, A., Lanza, L., Rizzo, A., Schaerf, C., Zonta, I., Filippi, A., Fegan, S., Kunkel, M., Bashkanov, M., Beltrame, P., Murphy, A., Smith, G., Watts, D., Zachariou, N., Zana, L., Glazier, D., Ireland, D., McKinnon, B., Sokhan, D., Colaneri, L., Pereira, S. Anefalos, Afanasev, A., Briscoe, B., Strakovsky, I., Kalantarians, N., Weinstein, L., Adhikari, K. P., Dunne, J. A., Dutta, D., Fassi, L. El, Ye, L., Hicks, K., Cole, P., Dobbs, S., and Fanelli, C.
Subjects: High Energy Physics - Experiment, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This proposal presents the MeV-GeV DM discovery potential for a $\sim$1 m$^3$ segmented CsI(Tl) scintillator detector placed downstream of the Hall A beam-dump at Jefferson Lab, receiving up to 10$^{22}$ electrons-on-target (EOT) in 285 days. This experiment (Beam-Dump eXperiment or BDX) would be sensitive to elastic DM-electron and to inelastic DM scattering at the level of 10 counts per year, reaching the limit of the neutrino irreducible background. The distinct signature of a DM interaction will be an electromagnetic shower of few hundreds of MeV, together with a reduced activity in the surrounding active veto counters. A detailed description of the DM particle $\chi$ production in the dump and subsequent interaction in the detector has been performed by means of Monte Carlo simulations. Different approaches have been used to evaluate the expected backgrounds: the cosmogenic background has been extrapolated from the results obtained with a prototype detector running at INFN-LNS (Italy), while the beam-related background has been evaluated by GEANT4 Monte Carlo simulations. The proposed experiment will be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments in the MeV-GeV DM mass range by up to two orders of magnitude., Comment: Proposal submitted to the 44th JLab PAC. 125 pages, 60 figures
Published: 2016

21. Spectroscopy of the neutron-rich hypernucleus $^{7}_{\Lambda}$He from electron scattering

Author: Gogami, T., Chen, C., Kawama, D., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Baturin, P., Badui, R., Boeglin, W., Bono, J., Brash, E., Carter, P., Chiba, A., Christy, E., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fujii, Y., Fujita, M., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Han, Y., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed. V., Jones, M., Kanda, H., Kaneta, M., Kato, S., Kawai, M., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Margaryan, A., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Qiu, X., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Tang, L., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Ya, L., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: The missing mass spectroscopy of the $^{7}_{\Lambda}$He hypernucleus was performed, using the $^{7}$Li$(e,e^{\prime}K^{+})^{7}_{\Lambda}$He reaction at the Thomas Jefferson National Accelerator Facility Hall C. The $\Lambda$ binding energy of the ground state (1/2$^{+}$) was determined with a smaller error than that of the previous measurement, being $B_{\Lambda}$ = 5.55 $\pm$ 0.10(stat.) $\pm$ 0.11(sys.) MeV. The experiment also provided new insight into charge symmetry breaking in p-shell hypernuclear systems. Finally, a peak at $B_{\Lambda}$ = 3.65 $\pm$ 0.20(stat.) $\pm$ 0.11(sys.) MeV was observed and assigned as a mixture of 3/2$^{+}$ and 5/2$^{+}$ states, confirming the "gluelike" behavior of $\Lambda$, which makes an unstable state in $^{6}$He stable against neutron emission., Comment: 6 pages, 4 figures
Published: 2016
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22. High Resolution Spectroscopic Study of $^{10}_{\Lambda}$Be

Author: Gogami, T., Chen, C., Kawama, D., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Baturin, P., Badui, R., Boeglin, W., Bono, J., Brash, E., Carter, P., Chiba, A., Christy, E., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fujii, Y., Fujita, M., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Han, Y., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed. V., Jones, M., Kanda, H., Kaneta, M., Kato, S., Kawai, M., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Margaryan, A., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Qiu, X., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Tang, L., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Ya, L., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: Spectroscopy of a $^{10}_{\Lambda}$Be hypernucleus was carried out at JLab Hall C using the $(e,e^{\prime}K^{+})$ reaction. A new magnetic spectrometer system (SPL+HES+HKS), specifically designed for high resolution hypernuclear spectroscopy, was used to obtain an energy spectrum with a resolution of 0.78 MeV (FWHM). The well-calibrated spectrometer system of the present experiment using the $p(e,e^{\prime}K^{+})\Lambda,\Sigma^{0}$ reactions allowed us to determine the energy levels, and the binding energy of the ground state peak (mixture of 1$^{-}$ and 2$^{-}$ states) was obtained to be B$_{\Lambda}$=8.55$\pm$0.07(stat.)$\pm$0.11(sys.) MeV. The result indicates that the ground state energy is shallower than that of an emulsion study by about 0.5 MeV which provides valuable experimental information on charge symmetry breaking effect in the $\Lambda N$ interaction., Comment: 6 figures
Published: 2015
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23. Electroexcitation of the $\Delta^{+}(1232)$ at low momentum transfer

Author: Blomberg, A., Anez, D., Sparveris, N., Sarty, A., Paolone, M., Gilad, S., Higinbotham, D., Abudureyimu, A. R., Ahmed, Z., Albataineh, H., Allada, K., Anderson, B., Aniol, K., Annand, J., Averett, T., Baghdasaryan, H., Bai, X., Beck, A., Beck, S., Bellini, V., Benmokhtar, F., Boeglin, W., Camacho, C. M., Camsonne, A., Chen, C., Chen, J. P., Chirapatpimol, K., Cisbani, E., Dalton, M., Deconinck, W., Defurne, M., De Leo, R., Flay, D., Fomin, N., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gilman, R., Gu, C., Hamilton, D., Hanretty, C., Hansen, O., Shabestari, M. Hashemi, Holmstrom, T., Huang, M., Iqbal, S., Kalantarians, N., Kang, H., Kelleher, A., Khandaker, M., Leckey, J., LeRose, J., Lindgren, R., Long, E., Mammei, J., Margaziotis, D. J., Jimenez-Arguello, A. Marti, Meziani, Z. E., Mihovilovic, M., Muangma, N., Norum, B., Nuruzzaman, Pan, K., Phillips, S., Polychronopoulou, A., Pomerantz, I., Posik, M., Punjabi, V., Qian, X., Reimer, P. E., Riordan, S., Ron, G., Saha, A., Schulte, E., Selvy, L., Sirca, S., Sjoegren, J., Subedi, R., Sulkosky, V., Tireman, W., Wang, D., Watson, J., Weinstein, L., Wojtsekhowski, B., Yan, W., Yaron, I., Ye, Z., Zhan, X., Zhang, Y., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: Nuclear Experiment
Abstract: We report on new p$(e,e^\prime p)\pi^\circ$ measurements at the $\Delta^{+}(1232)$ resonance at the low momentum transfer region. The mesonic cloud dynamics is predicted to be dominant and rapidly changing in this kinematic region offering a test bed for chiral effective field theory calculations. The new data explore the low $Q^2$ dependence of the resonant quadrupole amplitudes while extending the measurements of the Coulomb quadrupole amplitude to the lowest momentum transfer ever reached. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The reported measurements suggest that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements.
Published: 2015
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24. Transverse-target-spin asymmetry in exclusive $\omega$-meson electroproduction

Author: The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avetissian, A., Belostotski, S., Blok, H. P., Borissov, A., Bryzgalov, V., Capitani, G. P., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Elbakian, G., Ellinghaus, F., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Gharibyan, V., Giordano, F., Gliske, S., Hasch, D., Hoek, M., Holler, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Lorenzon, W., Ma, B. -Q., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Miyachi, Y., Movsisyan, A., Muccifora, V., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schnell, G., Seitz, B., Shibata, T. -A., Statera, M., Steffens, E., Steijger, J. J. M., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Yen, S., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Hard exclusive electroproduction of $\omega$ mesons is studied with the HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off a transversely polarized hydrogen target. The amplitudes of five azimuthal modulations of the single-spin asymmetry of the cross section with respect to the transverse proton polarization are measured. They are determined in the entire kinematic region as well as for two bins in photon virtuality and momentum transfer to the nucleon. Also, a separation of asymmetry amplitudes into longitudinal and transverse components is done. These results are compared to a phenomenological model that includes the pion pole contribution. Within this model, the data favor a positive $\pi\omega$ transition form factor., Comment: DESY Report 15-149
Published: 2015

25. Bose-Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

Author: HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., García, J. Garay, Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Lu, X. -G., Ma, B. -Q., Mahon, D., Makins, N. C. R., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stahl, M., Stancari, M., Statera, M., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Bose-Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of $^1$H, $^2$H, $^3$He, $^4$He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose-Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose-Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidence for a dependence on the invariant mass W of the photon-nucleon system is found when the results are compared to those of previous experiments.
Published: 2015

26. Measurement of the Target-Normal Single-Spin Asymmetry in Quasi-Elastic Scattering from the Reaction $^3$He$^\uparrow(e,e^\prime)$

Author: Zhang, Y. -W., Long, E., Mihovilovič, M., Jin, G., Allada, K., Anderson, B., Annand, J. R. M., Averett, T., Boeglin, W., Bradshaw, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. P., Chudakov, E., De Leo, R., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Frullani, S., Garibaldi, F., Gao, H., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Ibrahim, H., de Jager, C. W., Jensen, E., Jiang, X., John, J. St., Jones, M., Kang, H., Katich, J., Khanal, H. P., King, P., Korsch, W., LeRose, J., Lindgren, R., Lu, H. -J., Luo, W., Markowitz, P., Meziane, M., Michaels, R., Moffit, B., Monaghan, P., Muangma, N., Nanda, S., Norum, B. E., Pan, K., Parno, D., Piasetzky, E., Posik, M., Punjabi, V., Puckett, A. J. R., Qian, X., Qiang, Y., Qiu, X., Riordan, S., Ron, G., Saha, A., Sawatzky, B., Schiavilla, R., Schoenrock, B., Shabestari, M., Shahinyan, A., Širca, S., Subedi, R., Sulkosky, V., Tobias, W. A., Tireman, W., Urciuoli, G. M., Wang, D., Wang, K., Wang, Y., Watson, J., Wojtsekhowski, B., Ye, Y., Ye, Z., Zhan, X., Zhang, Y., Zheng, X., Zhao, B., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: We report the first measurement of the target single-spin asymmetry, $A_y$, in quasi-elastic scattering from the inclusive reaction $^3$He$^{\uparrow}(e,e^\prime)$ on a $^3$He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A non-zero $A_y$ can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the sub-structure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at $Q^{2}=$ 0.13, 0.46 and 0.97 GeV$^{2}$. These measurements demonstrate, for the first time, that the $^3$He asymmetry is clearly non-zero and negative with a statistical significance of (8-10)$\sigma$. Using measured proton-to-$^{3}$He cross-section ratios and the effective polarization approximation, neutron asymmetries of $-$(1-3)% were obtained. The neutron asymmetry at high $Q^2$ is related to moments of the Generalized Parton Distributions (GPDs). Our measured neutron asymmetry at $Q^2=0.97$ GeV$^2$ agrees well with a prediction based on two-photon exchange using a GPD model and thus provides a new, independent constraint on these distributions.
Published: 2015
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27. Double Spin Asymmetries of Inclusive Hadron Electroproductions from a Transversely Polarized $^3\rm{He}$ Target

Author: The Jefferson Lab Hall A Collaboration, Zhao, Y. X., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muñoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, W. A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Wang, Y., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: We report the measurement of beam-target double-spin asymmetries ($A_\text{LT}$) in the inclusive production of identified hadrons, $\vec{e}~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a longitudinally polarized 5.9 GeV electron beam and a transversely polarized $^3\rm{He}$ target. Hadrons ($\pi^{\pm}$, $K^{\pm}$ and proton) were detected at 16$^{\circ}$ with an average momentum $<$$P_h$$>$=2.35 GeV/c and a transverse momentum ($p_{T}$) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the $^3\text{He}$ target were observed to be non-zero for $\pi^{\pm}$ production when the target was polarized transversely in the horizontal plane. The $\pi^{+}$ and $\pi^{-}$ asymmetries have opposite signs, analogous to the behavior of $A_\text{LT}$ in semi-inclusive deep-inelastic scattering., Comment: Published in PRC (92.015207), nuclear experiment, high-energy experiment
Published: 2015
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28. Electroexcitation of the Δ+(1232) at low momentum transfer

Author: Blomberg, A, Anez, D, Sparveris, N, Sarty, AJ, Paolone, M, Gilad, S, Higinbotham, D, Ahmed, Z, Albataineh, H, Allada, K, Anderson, B, Aniol, K, Annand, J, Arrington, J, Averett, T, Baghdasaryan, H, Bai, X, Beck, A, Beck, S, Bellini, V, Benmokhtar, F, Boeglin, W, Camacho, CM, Camsonne, A, Chen, C, Chen, JP, Chirapatpimol, K, Cisbani, E, Dalton, M, Deconinck, W, Defurne, M, De Leo, R, Flay, D, Fomin, N, Friend, M, Frullani, S, Fuchey, E, Garibaldi, F, Gilman, R, Gu, C, Hamilton, D, Hanretty, C, Hansen, O, Hashemi Shabestari, M, Hen, O, Holmstrom, T, Huang, M, Iqbal, S, Kalantarians, N, Kang, H, Kelleher, A, Khandaker, M, Korover, I, Leckey, J, LeRose, J, Lindgren, R, Long, E, Mammei, J, Margaziotis, DJ, Martí Jimenez-Arguello, A, Meekins, D, Meziani, ZE, Mihovilovic, M, Muangma, N, Norum, B, Nuruzzaman, Pan, K, Phillips, S, Piasetzky, E, Polychronopoulou, A, Pomerantz, I, Posik, M, Punjabi, V, Qian, X, Rakhman, A, Reimer, PE, Riordan, S, Ron, G, Saha, A, Schulte, E, Selvy, L, Shneor, R, Sirca, S, Sjoegren, J, Subedi, R, Sulkosky, V, Tireman, W, Wang, D, Watson, J, Wojtsekhowski, B, Yan, W, Yaron, I, Ye, Z, Zhan, X, Zhang, J, Zhang, Y, Zhao, B, Zhao, Z, Zheng, X, and Zhu, P
Subjects: CMR, Pion electroproduction, Nucleon deformation, Nuclear & Particles Physics, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract: We report on new measurements at the resonance at the low momentum transfer region, where the mesonic cloud dynamics is predicted to be dominant and rapidly changing, offering a test bed for chiral effective field theory calculations. The new data explore the dependence of the resonant quadrupole amplitudes and for the first time indicate that the Electric and the Coulomb quadrupole amplitudes converge as. The measurements of the Coulomb quadrupole amplitude have been extended to the lowest momentum transfer ever reached, and suggest that more than half of its magnitude is attributed to the mesonic cloud in this region. The new data disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The measurements indicate that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements.
Published: 2016

29. Pentaquark $\Theta^+$ search at HERMES

Author: The HERMES Collaboration, Akopov, N., Akopov, Z., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Blok, H. P., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Di Nezza, P., Elbakian, G., Etzelmüller, E., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., García, J. Garay, Garibaldi, F., Gavrilov, G., Giordano, F., Gliske, S., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Ruiz, A. López, Lorenzon, W., Lu, X., Ma, B. -Q., Mahon, D., Manaenkov, S. I., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Nappi, E., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schnell, G., Schüler, K. P., Seitz, B., Shibata, T. -A., Stancari, M., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, H., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment
Abstract: The earlier search at HERMES for narrow baryon states excited in quasi-real photoproduction, decaying through the channel $pK_S^0\rightarrow p\pi^+\pi^-$, has been extended with improved decay-particle reconstruction, more advanced particle identification, and increased event samples. The structure observed earlier at an invariant mass of 1528 MeV shifts to 1522 MeV and the statistical significance drops to about 2$\sigma$ for data taken with a deuterium target. The number of events above background is $68_{-31}^{+98}\text{(stat)}\pm13\text{(sys)}$. No such structure is observed in the hydrogen data set.
Published: 2014
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30. The MOLLER Experiment: An Ultra-Precise Measurement of the Weak Mixing Angle Using M{\o}ller Scattering

Author: MOLLER Collaboration, Benesch, J., Brindza, P., Carlini, R. D., Chen, J-P., Chudakov, E., Covrig, S., Dalton, M. M., Deur, A., Gaskell, D., Gavalya, A., Gomez, J., Higinbotham, D. W., Keppel, C., Meekins, D., Michaels, R., Moffit, B., Roblin, Y., Suleiman, R., Wines, R., Wojtsekhowski, B., Cates, G., Crabb, D., Day, D., Gnanvo, K., Keller, D., Liyanage, N., Nelyubin, V. V., Nguyen, H., Norum, B., Paschke, K., Sulkosky, V., Zhang, J., Zheng, X., Birchall, J., Blunden, P., Gericke, M. T. W., Falk, W. R., Lee, L., Mammei, J., Page, S. A., van Oers, W. T. H., Dehmelt, K., Deshpande, A., Feege, N., Hemmick, T. K., Kumar, K. S., Kutz, T., Miskimen, R., Ramsey-Musolf, M. J., Riordan, S., Saylor, N. Hirlinger, Bessuille, J., Ihloff, E., Kelsey, J., Kowalski, S., Silwal, R., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Bellini, E. NappiV., Mammoliti, F., Noto, F., Sperduto, M. L., Sutera, C. M., Cole, P., Forest, T. A., Khandekar, M., McNulty, D., Aulenbacher, K., Baunack, S., Maas, F., Tioukine, V., Gilman, R., Myers, K., Ransome, R., Tadepalli, A., Beniniwattha, R., Holmes, R., Souder, P., Armstrong, D. S., Averett, T. D., Deconinck, W., Duvall, W., Lee, A., Pitt, M. L., Dunne, J. A., Dutta, D., Fassi, L. El, De Persio, F., Meddi, F., Urciuoli, G. M., Cisbani, E., Fanelli, C., Garibaldi, F., Johnston, K., Simicevic, N., Wells, S., King, P. M., Roche, J., Arrington, J., Reimer, P. E., Franklin, G., Quinn, B., Ahmidouch, A., Danagoulian, S., Glamazdin, O., Pomatsalyuk, R., Mammei, R., Martin, J. W., Holmstrom, T., Erler, J., Kolomensky, Yu. G., Napolitano, J., Aniol, K. A., Ramsay, W. D., Korkmaz, E., Spayde, D. T., Benmokhtar, F., Del Dotto, A., Perrino, R., Barkanova, S., Aleksejevs, A., and Singh, J.
Subjects: Nuclear Experiment, High Energy Physics - Phenomenology
Abstract: The physics case and an experimental overview of the MOLLER (Measurement Of a Lepton Lepton Electroweak Reaction) experiment at the 12 GeV upgraded Jefferson Lab are presented. A highlight of the Fundamental Symmetries subfield of the 2007 NSAC Long Range Plan was the SLAC E158 measurement of the parity-violating asymmetry $A_{PV}$ in polarized electron-electron (M{\o}ller) scattering. The proposed MOLLER experiment will improve on this result by a factor of five, yielding the most precise measurement of the weak mixing angle at low or high energy anticipated over the next decade. This new result would be sensitive to the interference of the electromagnetic amplitude with new neutral current amplitudes as weak as $\sim 10^{-3}\cdot G_F$ from as yet undiscovered dynamics beyond the Standard Model. The resulting discovery reach is unmatched by any proposed experiment measuring a flavor- and CP-conserving process over the next decade, and yields a unique window to new physics at MeV and multi-TeV scales, complementary to direct searches at high energy colliders such as the Large Hadron Collider (LHC). The experiment takes advantage of the unique opportunity provided by the upgraded electron beam energy, luminosity, and stability at Jefferson Laboratory and the extensive experience accumulated in the community after a round of recent successfully completed parity-violating electron scattering experiments
Published: 2014

31. Measurement of Parity-Violating Asymmetry in Electron-Deuteron Inelastic Scattering

Author: Wang, D., Pan, K., Subedi, R., Ahmed, Z., Allada, K., Aniol, K. A., Armstrong, D. S., Arrington, J., Bellini, V., Beminiwattha, R., Benesch, J., Benmokhtar, F., Bertozzi, W., Camsonne, A., Canan, M., Cates, G. D., Chen, J. -P., Chudakov, E., Cisbani, E., Dalton, M. M., de Jager, C. W., De Leo, R., Deconinck, W., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Erler, J., Flay, D., Franklin, G. B., Friend, M., Frullani, S., Garibaldi, F., Gilad, S., Giusa, A., Glamazdin, A., Golge, S., Grimm, K., Hafidi, K., Hansen, J. -O., Higinbotham, D. W., Holmes, R., Holmstrom, T., Holt, R. J., Huang, J., Hyde, C. E., Jen, C. M., Jones, D., Kang, Hoyoung, King, P. M., Kowalski, S., Kumar, K. S., Lee, J. H., LeRose, J. J., Liyanage, N., Long, E., McNulty, D., Margaziotis, D. J., Meddi, F., Meekins, D. G., Mercado, L., Meziani, Z. -E., Michaels, R., Mihovilovic, M., Muangma, N., Mesick, K. E., Nanda, S., Narayan, A., Nelyubin, V., Nuruzzaman, A., Oh, Y., Parno, D., Paschke, K. D., Phillips, S. K., Qian, X., Qiang, Y., Quinn, B., Rakhman, A., Reimer, P. E., Rider, K., Riordan, S., Roche, J., Rubin, J., Russo, G., Saenboonruang, K., Saha, A., Sawatzky, B., Shahinyan, A., Silwal, R., Širca, S., Souder, P. A., Suleiman, R., Sulkosky, V., Sutera, C. M., Tobias, W. A., Urciuoli, G. M., Waidyawansa, B., Wojtsekhowski, B., Ye, L., Zhao, B., and Zheng, X.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The parity-violating asymmetries between a longitudinally-polarized electron beam and an unpolarized deuterium target have been measured recently. The measurement covered two kinematic points in the deep inelastic scattering region and five in the nucleon resonance region. We provide here details of the experimental setup, data analysis, and results on all asymmetry measurements including parity-violating electron asymmetries and those of inclusive pion production and beam-normal asymmetries. The parity-violating deep-inelastic asymmetries were used to extract the electron-quark weak effective couplings, and the resonance asymmetries provided the first evidence for quark-hadron duality in electroweak observables. These electron asymmetries and their interpretation were published earlier, but are presented here in more detail., Comment: 50 pages, submitted to Phys. Rev. C
Published: 2014
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32. Measurement of double-polarization asymmetries in the quasi-elastic $^3\vec{\mathrm{He}}(\vec{\mathrm{e}},\mathrm{e}'\mathrm{d})$ process

Author: The Jefferson Lab Hall A Collaboration, Mihovilovič, M., Jin, G., Long, E., Zhang, Y. -W., Allada, K., Anderson, B., Annand, J. R. M., Averett, T., Boeglin, W., Bradshaw, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. P., Chudakov, E., De Leo, R., Deng, X., Deltuva, A., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Frullani, S., Garibaldi, F., Gao, H., Gilad, S., Gilman, R., Glamazdin, O., Golak, J., Golge, S., Gomez, J., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Ibrahim, H., de Jager, C. W., Jensen, E., Jiang, X., Jones, M., Kang, H., Katich, J., Khanal, H. P., Kievsky, A., King, P., Korsch, W., LeRose, J., Lindgren, R., Lu, H. -J., Luo, W., Marcucci, L. E., Markowitz, P., Meziane, M., Michaels, R., Moffit, B., Monaghan, P., Muangma, N., Nanda, S., Norum, B. E., Pan, K., Parno, D., Piasetzky, E., Posik, M., Punjabi, V., Puckett, A. J. R., Qian, X., Qiang, Y., Qui, X., Riordan, S., Saha, A., Sauer, P. U., Sawatzky, B., Schiavilla, R., Shabestari, M., Shahinyan, A., Schoenrock, B., Širca, S., Skibiński, R., John, J. St., Subedi, R., Sulkosky, V., Tobias, W. A., Tireman, W., Urciuoli, G. M., Viviani, M., Wang, D., Wang, K., Wang, Y., Watson, J., Wojtsekhowski, B., Witała, H., Ye, Z., Zhan, X., Zhang, Y., Zheng, X., Zhao, B., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: We present a precise measurement of double-polarization asymmetries in the $^3\vec{\mathrm{He}}(\vec{\mathrm{e}},\mathrm{e}'\mathrm{d})$ reaction. This particular process is a uniquely sensitive probe of hadron dynamics in $^3\mathrm{He}$ and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasi-elastic kinematics at $Q^2 = 0.25\,(\mathrm{GeV}/c)^2$ for missing momenta up to $270\,\mathrm{MeV}/c$. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on $p_\mathrm{m}$ and $\omega$, but are systematically offset. Beyond the region of the quasi-elastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two- and/or three-body dynamics is required., Comment: 6 pages, 4 figures, accepted for publication at Phys. Rev. Lett
Published: 2014
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33. Spin density matrix elements in exclusive $\omega$ electroproduction on $^1$H and $^2$H targets at 27.5 GeV beam energy

Author: The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Augustyniak, W., Avetissian, A., Blok, H. P., Borissov, A., Bryzgalov, V., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Lorenzon, W., Ma, B. -Q., Mahon, D., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Movsisyan, A., Murray, M., Naryshkin, Y., Nass, A., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rostomyan, A., Ryckbosch, D., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shibata, T. -A., Stahl, M., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Yen, S., Zeiler, D., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Exclusive electroproduction of $\omega$ mesons on unpolarized hydrogen and deuterium targets is studied in the kinematic region of Q$^2$>1.0 GeV$^2$, 3.0 GeV < W < 6.3 GeV, and -t'< 0.2 GeV$^2$. Results on the angular distribution of the $\omega$ meson, including its decay products, are presented. The data were accumulated with the HERMES forward spectrometer during the 1996-2007 running period using the 27.6 GeV longitudinally polarized electron or positron beam of HERA. The determination of the virtual-photon longitudinal-to-transverse cross-section ratio reveals that a considerable part of the cross section arises from transversely polarized photons. Spin density matrix elements are presented in projections of Q$^2$ or -t'. Violation of s-channel helicity conservation is observed for some of these elements. A sizable contribution from unnatural-parity-exchange amplitudes is found and the phase shift between those amplitudes that describe transverse $\omega$ production by longitudinal and transverse virtual photons, $\gamma^{*}_{L} \to \omega_{T}$ and $\gamma^{*}_{T} \to \omega_{T}$, is determined for the first time. A hierarchy of helicity amplitudes is established, which mainly means that the unnatural-parity-exchange amplitude describing the $\gamma^*_T \to \omega_T$ transition dominates over the two natural-parity-exchange amplitudes describing the $\gamma^*_L \to \omega_L$ and $\gamma^*_T \to \omega_T$ transitions, with the latter two being of similar magnitude. Good agreement is found between the HERMES proton data and results of a pQCD-inspired phenomenological model that includes pion-pole contributions, which are of unnatural parity., Comment: "Erratum version", e.g., includes the corrected version of Figure 6, to be published in "Erratum to: Spin density matrix elements in exclusive omega electroproduction on 1H and 2H targets at 27.5 GeV beam energy". Three SDMEs were mislabeled in the figure of the previously published version [EPJC74(2014)3110]. The labels have been fixed, while none of the results or conclusions changed
Published: 2014

34. Transverse polarization of $\Lambda$ hyperons from quasireal photoproduction on nuclei

Author: The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Lu, X. -G., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yu, W., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: The transverse polarization of $\Lambda$ hyperons was measured in inclusive quasireal photoproduction for various target nuclei ranging from hydrogen to xenon. The data were obtained by the HERMES experiment at HERA using the 27.6 GeV lepton beam and nuclear gas targets internal to the lepton storage ring. The polarization observed is positive for light target nuclei and is compatible with zero for krypton and xenon., Comment: final version to be published in Phys. Rev. D (in press)
Published: 2014
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35. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

Author: BDX Collaboration, Battaglieri, M., Celentano, A., De Vita, R., Izaguirre, E., Krnjaic, G., Smith, E., Stepanyan, S., Bersani, A., Fanchini, E., Fegan, S., Musico, P., Osipenko, M., Ripani, M., Santopinto, E., Taiuti, M., Schuster, P., Toro, N., Dalton, M., Freyberger, A., Girod, F. -X., Kubarovsky, V., Ungaro, M., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Nappi, E., Perrino, R., Carpinelli, M., Sipala, V., Aiello, S., Bellini, V., De Napoli, M., Giusa, A., Mammoliti, F., Leonora, E., Noto, F., Randazzo, N., Russo, G., Sperduto, M., Sutera, C., Ventura, C., Barion, L., Ciullo, G., Contalbrigo, M., Lenisa, P., Movsisyan, A., Spizzo, F., Turisini, M., De Persio, F., Cisbani, E., Fanelli, C., Garibaldi, F., Meddi, F., Urciuoli, G. M., Pereira, S. Anefalos, De Sanctis, E., Hasch, D., Lucherini, V., Mirazita, M., Montgomery, R., Pisano, S., Simi, G., D'Angelo, A., Lanza, L. Colaneri L., Rizzo, A., Schaerf, C., Zonta, I., Calvo, D., Filippi, A., Holtrop, M., Peremuzyan, R., Glazier, D., Ireland, D., McKinnon, B., Afanasev, D. Sokhan A., Briscoe, B., Kalantarians, N., Fassi, L. El, Weinstein, L., Beltrame, P., Murphy, A., Watts, D., Zana, L., and Hicks, K.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This Letter of Intent presents the MeV-GeV DM discovery potential for a 1 m$^3$ segmented plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls, receiving up to 10$^{22}$ electrons-on-target (EOT) in a one-year period. This experiment (Beam-Dump eXperiment or BDX) is sensitive to DM-nucleon elastic scattering at the level of a thousand counts per year, with very low threshold recoil energies ($\sim$1 MeV), and limited only by reducible cosmogenic backgrounds. Sensitivity to DM-electron elastic scattering and/or inelastic DM would be below 10 counts per year after requiring all electromagnetic showers in the detector to exceed a few-hundred MeV, which dramatically reduces or altogether eliminates all backgrounds. Detailed Monte Carlo simulations are in progress to finalize the detector design and experimental set up. An existing 0.036 m$^3$ prototype based on the same technology will be used to validate simulations with background rate estimates, driving the necessary R$\&$D towards an optimized detector. The final detector design and experimental set up will be presented in a full proposal to be submitted to the next JLab PAC. A fully realized experiment would be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments by two orders of magnitude in the MeV-GeV DM mass range., Comment: 28 pages, 17 figures, submitted to JLab PAC 42
Published: 2014

36. The experiments with the High Resolution Kaon Spectrometer at JLab Hall C and the new spectroscopy of ${}^{12}_{\Lambda}\text{B}$ hypernuclei

Author: Tang, L., Chen, C., Gogami, T., Kawama, D., Han, Y., Yuan, L., Matsumura, A., Okayasu, Y., Seva, T., Rodriguez, V. M., Baturin, P., Acha, A., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Badui, R., Baker, O. K., Benmokhtar, F., Boeglin, W., Bono, J., Bosted, P., Brash, E., Carter, P., Carlini, R., Chiba, A., Christy, M. E., Cole, L., Dalton, M. M., Danagoulian, S., Daniel, A., De Leo, R., Dharmawardane, V., Doi, D., Egiyan, K., Elaasar, M., Ent, R., Fenker, H., Fujii, Y., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Gibson, E. F., Gueye, P., Hashimoto, O., Honda, D., Horn, T., Hu, B., Hungerford, Ed V., Jayalath, C., Jones, M., Johnston, K., Kalantarians, N., Kanda, H., Kaneta, M., Kato, F., Kato, S., Kawai, M., Keppel, C., Khanal, H., Kohl, M., Kramer, L., Lan, K. J., Li, Y., Liyanage, A., Luo, W., Mack, D., Maeda, K., Malace, S., Margaryan, A., Marikyan, G., Markowitz, P., Maruta, T., Maruyama, N., Maxwell, V., Millener, D. J., Miyoshi, T., Mkrtchyan, A., Mkrtchyan, H., Motoba, T., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Nomura, H., Nonaka, K., Ohtani, A., Oyamada, M., Perez, N., Petkovic, T., Pochodzalla, J., Qiu, X., Randeniya, S., Raue, B., Reinhold, J., Rivera, R., Roche, J., Samanta, C., Sato, Y., Sawatzky, B., Segbefia, E. K., Schott, D., Shichijo, A., Simicevic, N., Smith, G., Song, Y., Sumihama, M., Tadevosyan, V., Takahashi, T., Taniya, N., Tsukada, K., Tvaskis, V., Veilleux, M., Vulcan, W., Wells, S., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Yan, C., Ye, Z., Yokota, K., Zhamkochyan, S., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: Since the pioneering experiment, E89-009 studying hypernuclear spectroscopy using the $(e,e^{\prime}K^+)$ reaction was completed, two additional experiments, E01-011 and E05-115, were performed at Jefferson Lab. These later experiments used a modified experimental design, the "tilt method", to dramatically suppress the large electromagnetic background, and allowed for a substantial increase in luminosity. Additionally, a new kaon spectrometer, HKS (E01-011), a new electron spectrometer, HES, and a new splitting magnet were added to produce precision, high-resolution hypernuclear spectroscopy. These two experiments, E01-011 and E05-115, resulted in two new data sets, producing sub-MeV energy resolution in the spectra of ${}^{7}_{\Lambda}\text{He}$, ${}^{12}_{\Lambda}\text{B}$ and ${}^{28}_{\Lambda}\text{Al}$ and ${}^{7}_{\Lambda}\text{He}$, ${}^{10}_{\Lambda}\text{Be}$, ${}^{12}_{\Lambda}\text{B}$ and ${}^{52}_{\Lambda}\text{V}$. All three experiments obtained a ${}^{12}_{\Lambda}\text{B}$, spectrum, which is the most characteristic $p$-shell hypernucleus and is commonly used for calibration. Independent analyses of these different experiments demonstrate excellent consistency and provide the clearest level structure to date of this hypernucleus as produced by the $(e,e^{\prime}K^+)$ reaction. This paper presents details of these experiments, and the extraction and analysis of the observed ${}^{12}_{\Lambda}\text{B}$ spectrum.
Published: 2014
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37. Spectroscopy of Lambda-9Li by electroproduction

Author: Urciuoli, G. M., Cusanno, F., Marrone, S., Acha, A., Ambrozewicz, P., Aniol, K. A., Baturin, P., Bertin, P. Y., Benaoum, H., Blomqvist, K. I., Boeglin, W. U., Breuer, H., Brindza, P., Bydzovsky, P., Camsonne, A., Chang, C. C., Chen, J. -P., Choi, Seonho, Chudakov, E. A., Cisbani, E., Colilli, S., Coman, L., Craver, B. J., De Cataldo, G., de Jager, C. W., De Leo, R., Deur, A. P., Ferdi, C., Feuerbach, R. J., Folts, E., Fratoni, R., Frullani, S., Garibaldi, F., Gayou, O., Giuliani, F., Gomez, J., Gricia, M., Hansen, J. O., Hayes, D., Higinbotham, D. W., Holmstrom, T. K., Hyde, C. E., Ibrahim, H. F., Iodice, M., Jiang, X., Kaufman, L. J., Kino, K., Kross, B., Lagamba, L., LeRose, J. J., Lindgren, R. A., Lucentini, M., Margaziotis, D. J., Markowitz, P., Meziani, Z. E., McCormick, K., Michaels, R. W., Millener, D. J., Miyoshi, T., Moffit, B., Monaghan, P. A., Moteabbed, M., Camacho, C. Munoz, Nanda, S., Nappi, E., Nelyubin, V. V., Norum, B. E., Okasyasu, Y., Paschke, K. D., Perdrisat, C. F., Piasetzky, E., Punjabi, V. A., Qiang, Y., Reimer, P. E., Reinhold, J., Reitz, B., Roche, R. E., Rodriguez, V. M., Saha, A., Santavenere, F., Sarty, A. J., Segal, J., Shahinyan, A., Singh, J., Sirca, S., Snyder, R., Solvignon, P. H., Sotona, M., Subedi, R., Sulkosky, V. A., Suzuki, T., Ueno, H., Ulmer, P. E., Veneroni, P., Voutier, E., Wojtsekhowski, B. B., Zheng, X., and Zorn, C.
Subjects: Nuclear Experiment
Abstract: In the absence of accurate data on the free two-body hyperon-nucleon interaction, the spectra of hypernuclei can provide information on the details of the effective hyperon-nucleon interaction. Electroproduction of the hypernucleus Lambda-9Li has been studied for the first time with sub-MeV energy resolution in Hall A at Jefferson Lab on a 9Be target. In order to increase the counting rate and to provide unambiguous kaon identification, two superconducting septum magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A standard equipment. The cross section to low-lying states of Lambda-9Li is concentrated within 3 MeV of the ground state and can be fitted with four peaks. The positions of the doublets agree with theory while a disagreement could exist with respect to the relative strengths of the peaks in the doublets. A Lambda separation energy of 8.36 +- 0.08 (stat.) +- 0.08 (syst.) MeV was measured, in agreement with an earlier experiment., Comment: 14 pages, 8 figures
Published: 2014
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38. Single Spin Asymmetries in Charged Kaon Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized $^3{\rm{He}}$ Target

Author: Zhao, Y. X., Wang, Y., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muñoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.
Subjects: Nuclear Experiment
Abstract: We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized $^3{\rm{He}}$ target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1$<$$x_{bj}$$<$0.4 for $K^{+}$ and $K^{-}$ production. While the Collins and Sivers moments for $K^{+}$ are consistent with zero within the experimental uncertainties, both moments for $K^{-}$ favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. While the $K^{+}$ Sivers moments are consistent with the prediction, the $K^{-}$ results differ from the prediction at the 2-sigma level., Comment: 6 pages, 3 figures
Published: 2014
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39. Probing the Repulsive Core of the Nucleon-Nucleon Interaction via the 4He(e,e'pN) Triple-Coincidence Reaction

Author: Muangma, I. Korover N., Hen, O., Shneor, R., Sulkosky, V., Kelleher, A., Gilad, S., Higinbotham, D. W., Watson, E. Piasetzky J., Wood, S., Rakhman, Abdurahim, Aguilera, P., Ahmed, Z., Albataineh, H., Allada, K., Anderson, B., Anez, D., Aniol, K., Annand, J., Armstrong, W., Arrington, J., Averett, T., Badman, T., Baghdasaryan, H., Bai, X., Beck, A., Beck, S., Bellini, V., Benmokhtar, F., Bertozzi, W., Bittner, J., Boeglin, W., Camsonne, A., Chen, C., Chen, J. -P., Chirapatpimol, K., Cisbani, E., Dalton, M. M., Daniel, A., Day, D., de Jager, C. W., De Leo, R., Deconinck, W., Defurne, M., Flay, D., Fomin, N., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gaskell, D., Gilman, R., Glamazdin, O., Gu, C., Gueye, P., Hamilton, D., Hanretty, C., Hansen, O., Shabestari, M. Hashemi, Holmstrom, T., Huang, M., Iqbal, S., Jin, G., Kalantarians, N., Kang, H., Khandaker, M., LeRose, J., Leckey, J., Lindgren, R., Long, E., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meekins, D., Meziani, Z., Michaels, R., Mihovilovic, M., Monaghan, P., Camacho, C. Munoz, Norum, B., Nuruzzaman, Pan, K., Phillips, S., Pomerantz, I., Posik, M., Punjabi, V., Qian, X., Qiang, Y., Qiu, X., Reimer, P. E., Riordan, S., Ron, G., Rondon-Aramayo, O., Saha, A., Schulte, E., Selvy, L., Shahinyan, A., Sirca, S., Sjoegren, J., Slifer, K., Solvignon, P., Sparveris, N., Subedi, R., Tireman, W., Wang, D., Weinstein, L. B., Wojtsekhowski, B., Yan, W., Yaron, I., Ye, Z., Zhan, X., Zhang, J., Zhang, Y., Zhao, B., Zhao, Z., Zheng, X., Zhu, P., and Zielinski, R.
Subjects: Nuclear Experiment
Abstract: We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q^2=2 [GeV/c]2 and x_B>1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum in a region where the nucleon-nucleon force is expected to change from predominantly tensor to repulsive. Neutron-proton pairs dominate the high-momentum tail of the nucleon momentum distributions, but their abundance is reduced as the nucleon momentum increases beyond ~500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum in the range we studied. Our data are compared with ab-initio calculations of two-nucleon momentum distributions in 4He., Comment: 6 pages, 2 figures
Published: 2014
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40. Reevaluation of the parton distribution of strange quarks in the nucleon

Author: The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avetissian, A., Avetisyan, E., Belostotski, S., Blok, H. P., Borissov, A., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., García, J. Garay, Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Hartig, M., Hasch, D., Hoek, M., Holler, Y., Hristova, I., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Lorenzon, W., Ma, B. -Q., Mahon, D., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Stahl, M., Statera, M., Steffens, E., Steijger, J. J. M., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: An earlier extraction from the HERMES experiment of the polarization-averaged parton distribution of strange quarks in the nucleon has been reevaluated using final data on the multiplicities of charged kaons in semi-inclusive deep-inelastic scattering obtained with a kinematically more comprehensive method of correcting for experimental effects. General features of the distribution are confirmed, but the rise at low x is less pronounced than previously reported.
Published: 2013
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41. Measurement of pretzelosity asymmetry of charged pion production in Semi-Inclusive Deep Inelastic Scattering on a polarized $^3$He target

Author: Zhang, Y., Qian, X., Allada, K., Dutta, C., Huang, J., Katich, J., Wang, Y., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, M., Ibrahim, H. F., Iodice, M., Jiang, X., Jin, G., Jones, M. K., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muñoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qiang, Y., Rakhman, A., Ransome, R. D., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Sirca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, W. A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.
Subjects: Nuclear Experiment
Abstract: An experiment to measure single-spin asymmetries in semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized $^3$He target was performed at Jefferson Lab in the kinematic region of $0.16
Published: 2013
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42. The OLYMPUS Experiment

Author: Milner, R., Hasell, D. K., Kohl, M., Schneekloth, U., Akopov, N., Alarcon, R., Andreev, V. A., Ates, O., Avetisyan, A., Bayadilov, D., Beck, R., Belostotski, S., Bernauer, J. C., Bessuille, J., Brinker, F., Buck, B., Calarco, J. R., Carassiti, V., Cisbani, E., Ciullo, G., Contalbrigo, M., D'Ascenzo, N., De Leo, R., Diefenbach, J., Donnelly, T. W., Dow, K., Elbakian, G., Eversheim, D., Frullani, S., Funke, Ch., Gavrilov, G., Gläser, B., Görrissen, N., Hauschildt, J., Henderson, B. S., Hoffmeister, Ph., Holler, Y., Ice, L. D., Izotov, A., Kaiser, R., Karyan, G., Kelsey, J., Khaneft, D., Klassen, P., Kiselev, A., Krivshich, A., Lehmann, I., Lenisa, P., Lenz, D., Lumsden, S., Ma, Y., Maas, F., Marukyan, H., Miklukho, O., Movsisyan, A., Murray, M., Naryshkin, Y., O'Connor, C., Benito, R. Perez, Perrino, R., Redwine, R. P., Piñeiro, D. Rodríguez, Rosner, G., Russell, R. L., Schmidt, A., Seitz, B., Statera, M., Thiel, A., Vardanyan, H., Veretennikov, D., Vidal, C., Winnebeck, A., and Yeganov, V.
Subjects: Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract: The OLYMPUS experiment was designed to measure the ratio between the positron-proton and electron-proton elastic scattering cross sections, with the goal of determining the contribution of two-photon exchange to the elastic cross section. Two-photon exchange might resolve the discrepancy between measurements of the proton form factor ratio, $\mu_p G^p_E/G^p_M$, made using polarization techniques and those made in unpolarized experiments. OLYMPUS operated on the DORIS storage ring at DESY, alternating between 2.01~GeV electron and positron beams incident on an internal hydrogen gas target. The experiment used a toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight detectors to measure rates for elastic scattering over the polar angular range of approximately $25^\circ$--$75^\circ$. Symmetric M{\o}ller/Bhabha calorimeters at $1.29^\circ$ and telescopes of GEM and MWPC detectors at $12^\circ$ served as luminosity monitors. A total luminosity of approximately 4.5~fb$^{-1}$ was collected over two running periods in 2012. This paper provides details on the accelerator, target, detectors, and operation of the experiment., Comment: 40 pages, 26 figures
Published: 2013
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43. Single Spin Asymmetries of Inclusive Hadrons Produced in Electron Scattering from a Transversely Polarized $^3$He Target

Author: Allada, K., Zhao, Y. X., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Munoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Sirca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report the first measurement of target single-spin asymmetries (A$_N$) in the inclusive hadron production reaction, $e~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a transversely polarized $^3$He target. The experiment was conducted at Jefferson Lab in Hall A using a 5.9-GeV electron beam. Three types of hadrons ($\pi^{\pm}$, $\text{K}^{\pm}$ and proton) were detected in the transverse hadron momentum range 0.54 $
Published: 2013
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44. Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction $^{3}\mathrm{He}^{\uparrow}(e,e')X$

Author: Katich, J., Qian, X., Zhao, Y. X., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F., Iodice, M., Jiang, X., Jin, G., Jones, M. K., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muńoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qiang, Y., Rakhman, A., Ransome, R. D., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.
Subjects: Nuclear Experiment
Abstract: We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction $^3$He$^{\uparrow}\left(e,e' \right)X$ on a polarized $^3$He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be non-zero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of $1.7 < W < 2.9$ GeV, $1.02$ GeV, which is non-zero at the $2.89\sigma$ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering., Comment: This is the final edited version as published in PRL
Published: 2013
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45. Transverse target single-spin asymmetry in inclusive electroproduction of charged pions and kaons

Author: The HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Bianchi, N., Blok, H. P., Borissov, A., Bowles, J., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Yu, W., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle $\psi$ about the beam direction between the target-spin direction and the hadron production plane, the transverse hadron momentum relative to the direction of the incident beam, and the Feynman variable $x_F$. The $\sin(\psi)$ amplitudes are positive for positive pions and kaons, slightly negative for negative pions and consistent with zero for negative kaons, with particular transverse-momentum but weak $x_F$ dependences. Especially large asymmetries are observed for two small subsamples of events, where also the scattered electron was recorded by the spectrometer., Comment: 10 pages, 5 figures
Published: 2013

46. Beam-helicity asymmetry in associated electroproduction of real photons $ep \to e\gamma \pi N$ in the $\Delta$-resonance region

Author: The HERMES Collaboration, Airapetian, A., Akopov, N., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Blok, H. P., Böttcher, H., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Frullani, S., Gapienko, G., Gapienko, V., García, J. Garay, Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Hartig, M., Hasch, D., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Lorenzon, W., Lu, X. -G., Ma, B. -Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Mao, Y., Marianski, B., Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Muccifora, V., Murray, M., Mussgiller, A., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Stahl, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zagrebelnyy, V., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: The beam-helicity asymmetry in associated electroproduction of real photons, $ep\to e\gamma \pi N$, in the $\Delta$(1232)-resonance region is measured using the longitudinally polarized HERA positron beam and an unpolarized hydrogen target. Azimuthal Fourier amplitudes of this asymmetry are extracted separately for two channels, $ep\to e\gamma \pi^0 p$ and $ep\to e\gamma \pi^+ n$, from a data set collected with a recoil detector. All asymmetry amplitudes are found to be consistent with zero., Comment: 17 pages, 4 figures, (minor changes wit respect to previous arXiv version)
Published: 2013
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47. Measurement of the Parity-Violating Asymmetry in Electron-Deuteron Scattering in the Nucleon Resonance Region

Author: Wang, D., Pan, K., Subedi, R., Deng, X., Ahmed, Z., Allada, K., Aniol, K. A., Armstrong, D. S., Arrington, J., Bellini, V., Beminiwattha, R., Benesch, J., Benmokhtar, F., Camsonne, A., Canan, M., Cates, G. D., Chen, J. -P., Chudakov, E., Cisbani, E., Dalton, M. M., de Jager, C. W., De Leo, R., Deconinck, W., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Franklin, G. B., Friend, M., Frullani, S., Garibaldi, F., Giusa, A., Glamazdin, A., Golge, S., Grimm, K., Hafidi, K., Hansen, O., Higinbotham, D. W., Holmes, R., Holmstrom, T., Holt, R. J., Huang, J., Hyde, C. E., Jen, C. M., Jones, D., Kang, H., King, P., Kowalski, S., Kumar, K. S., Lee, J. H., LeRose, J. J., Liyanage, N., Long, E., McNulty, D., Margaziotis, D. J., Meddi, F., Meekins, D. G., Mercado, L., Meziani, Z. -E., Michaels, R., Mihovilovic, M., Muangma, N., Myers, K. E., Nanda, S., Narayan, A., Nelyubin, V., Nuruzzaman, Oh, Y., Parno, D., Paschke, K. D., Phillips, S. K., Qian, X., Qiang, Y., Quinn, B., Rakhman, A., Reimer, P. E., Rider, K., Riordan, S., Roche, J., Rubin, J., Russo, G., Saenboonruang, K., Saha, A., Sawatzky, B., Shahinyan, A., Silwal, R., Sirca, S., Souder, P. A., Suleiman, R., Sulkosky, V., Sutera, C. M., Tobias, W. A., Urciuoli, G. M., Waidyawansa, B., Wojtsekhowski, B., Ye, L., Zhao, B., and Zheng, X.
Subjects: Nuclear Experiment
Abstract: We report on parity-violating asymmetries in the nucleon resonance region measured using $5 - 6$ GeV longitudinally polarized electrons scattering off an unpolarized deuterium target. These results are the first parity-violating asymmetry data in the resonance region beyond the $\Delta(1232)$, and provide a verification of quark-hadron duality in the nucleon electroweak $\gamma Z$ interference structure functions at the (10-15)% level. The results are of particular interest to models relevant for calculating the $\gamma Z$ box-diagram corrections to elastic parity-violating electron scattering measurements., Comment: 7 pages, 1 figure, to appear in Phys. Rev. Lett
Published: 2013
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48. The HERMES Recoil Detector

Author: Airapetian, A., Aschenauer, E. C., Belostotski, S., Borissov, A., Borisenko, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capitani, G. P., Carassiti, V., Ciullo, G., Clarkson, A., Contalbrigo, M., De Leo, R., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Guler, H., Gregor, I. M., Hartig, M., Hill, G., Hoek, M., Holler, Y., Hristova, I., Jo, H. S., Kaiser, R., Keri, T., Kisselev, A., Krause, B., Krauss, B., Lagamba, L., Lehmann, I., Lenisa, P., Lu, S., Lu, X. -G., Lumsden, S., Mahon, D., de la Ossa, A. Martinez, Murray, M., Mussgiller, A., Nowak, W. -D., Naryshkin, Y., Osborne, A., Pappalardo, L. L., Perez-Benito, R., Petrov, A., Pickert, N., Prahl, V., Protopopescu, D., Reinecke, M., Riedl, C., Rith, K., Rosner, G., Rubacek, L., Ryckbosch, D., Salomatin, Y., Schnell, G., Seitz, B., Shearer, C., Shutov, V., Statera, M., Steijger, J. J. M., Stenzel, H., Stewart, J., Stinzing, F., Trzcinski, A., Tytgat, M., Vandenbroucke, A., Van Haarlem, Y., Van Hulse, C., Varanda, M., Veretennikov, D., Vilardi, I., Vikhrov, V., Vogel, C., Yaschenko, S., Ye, Z., Yu, W., Zeiler, D., and Zihlmann, B.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1 T. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system., Comment: 50 pages, 72 figures
Published: 2013
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49. A method to calibrate measurement instruments to optimize the spectrometer optics for experiment E94-107 at JLab

Author: Urciuoli, G.M., Cisbani, E., De Leo, R., Garibaldi, F., Higinbotham, D.W., LeRose, J.J., and Markowitz, P.
Published: 2019
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50. Multiplicities of charged pions and kaons from semi-inclusive deep-inelastic scattering by the proton and the deuteron

Author: HERMES Collaboration, Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., De Leo, R., De Nardo, L., De Sanctis, E., Diefenthaler, M., Di Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gabbert, D., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Hadjidakis, C., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Imazu, Y., Ivanilov, A., Izotov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Kobayashi, N., Korotkov, V., Kozlov, V., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. López, Lorenzon, W., Ma, B. -Q., Mahon, D., Maiheu, B., Makins, N. C. R., Manaenkov, S. I., Manfré, L., Mao, Y., Marianski, B., de la Ossa, A. Martinez, Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. -D., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Raithel, M., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanftl, F., Schäfer, A., Schnell, G., Seitz, B., Shibata, T. -A., Shutov, V., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stewart, J., Stinzing, F., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Van Haarlem, Y., Van Hulse, C., Veretennikov, D., Vilardi, I., Vogel, C., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Yu, W., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Multiplicities in semi-inclusive deep-inelastic scattering are presented for each charge state of \pi^\pm and K^\pm mesons. The data were collected by the HERMES experiment at the HERA storage ring using 27.6 GeV electron and positron beams incident on a hydrogen or deuterium gas target. The results are presented as a function of the kinematic quantities x_B, Q^2, z, and P_h\perp. They represent a unique data set for identified hadrons that will significantly enhance our understanding of the fragmentation of quarks into final-state hadrons in deep-inelastic scattering.
Published: 2012
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