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15 results on '"Saini M"'

1. On the dynamics of a collapsing bubble in contact with a rigid wall

Author

Saini, M, Tanne, E, Arrigoni, M, Zaleski, S, and Fuster, D

Subjects
Physics - Fluid Dynamics
Abstract

This work reveals that the dynamic response of a spherical cap bubble in contact with a rigid wall depends on the effective contact angle at the instant prior to collapse. This parameter allows us to discriminate between two regimes in which the mechanisms of interaction between the collapsing bubble and its surrounding medium differ significantly: When the contact angle is smaller than 90 degrees a classical jet directed towards the wall is observed whereas if the initial contact angle is larger than 90 degrees an annular re-entrant jet parallel to the wall appears. We show that this change of the behaviour can be explained using the impulse potential flow theory for small times which shows the presence of a singularity on the initial acceleration of the contact line when the contact angle is larger then 90 degrees. Direct Numerical Simulations show that although viscosity regularises the solution at $t > 0$, the solution remains singular at $t=0$. In these circumstances numerical and experimental results show that the collapse of flat bubbles can eventually lead to the formation of a vortex ring that unexpectedly induces long-range effects. The role of the bubble geometry at the instant of maximum expansion on the overall collapse process is shown to be well captured by the impulse potential flow theory, which can be easily generalised to other bubble shapes. These results may find direct application in the interpretation of geophysical flows as well as the control and design of bio-medical, naval, manufacturing and sonochemistry applications.

Published
2024
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2. Exclusive $\eta$ electroproduction at $W>2$ GeV with CLAS and transversity generalized parton distributions

Author

CLAS Collaboration, Bedlinskiy, I., Kubarovsky, V., Stoler, P., Adhikari, K. P., Akbar, Z., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Garçon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Hughes, S. M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kuhn, S. E., Kuleshov, S. V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McKinnon, B., Meziani, Z. E., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Turisini, M., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Yurov, M., Zachariou, N., Zhang, J., and Zonta, I.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

The cross section of the exclusive $\eta$ electroproduction reaction $ep\to e^\prime p^\prime \eta$ was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\eta$ and structure functions $\sigma_U = \sigma_T+\epsilon\sigma_L, \sigma_{TT}$ and $\sigma_{LT}$, as functions of $t$ were obtained over a wide range of $Q^2$ and $x_B$. The $\eta$ structure functions are compared with those previously measured for $\pi^0$ at the same kinematics. At low $t$, both $\pi^0$ and $\eta$ are described reasonably well by generalized parton distributions (GPDs) in which chiral-odd transversity GPDs are dominant. The $\pi^0$ and $\eta$ data, when taken together, can facilitate the flavor decomposition of the transversity GPDs., Comment: 16 pages, 16 figures

Published
2017
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3. Target and beam-target spin asymmetries in exclusive pion electroproduction for $Q^2>1$ GeV$^2$. II. $e p \rightarrow e \pi^0 p$

Author

Bosted, P. E., Kim, A., Adhikari, K. P., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Badui, R. A., Ball, J., Balossino, I., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bültmann, S., Burkert, V. D., Cao, T., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chetry, T., Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fleming, J. A., Forest, T. A., Fradi, A., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Hakobyan, H., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Hollis, G., Holtrop, M., Hughes, S. M., Ireland, D. G., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joo, K., Keller, D., Khachatryan, G., Khandaker, M., Kim, W., Klei, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Lanza, L., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Markov, N., Mayer, M., McCracken, M. E., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V. I., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Murdoch, G., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pisano, S., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Schumacher, R. A., Seder, E., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Torayev, B., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $\pi^0$ electroproduction reaction $\gamma^* p \to p \pi^0$, expanding an analysis of the $\gamma^* p \to n \pi^+$ reaction from the same experiment. The results were obtained from scattering of 6 GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Lab. The kinematic range covered is $1.1

Published
2016
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4. Precision measurements of $g_1$ of the proton and the deuteron with 6 GeV electrons

Author

Prok, Y., Bosted, P., Kvaltine, N., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Biselli, A. S., Bono, J., Briscoe, W. J., Brock, J., Brooks, W. K., Bültmann, S., Burkert, V. D., Carlin, C., Carman, D. S., Celentano, A., Chandavar, S., Colaneri, L., Cole, P. L., Contalbrigo, M., Cortes, O., Crabb, D., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Forest, T. A., Garcon, M., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Giovanetti, K. L., Goetz, J. T., Gohn, W., Gothe, R. W., Griffioen, K. A., Guegan, B., Guler, N., Haffidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jawalkar, S., Jiang, X., Jo, H. S., Joo, K., Kalantarians, N., Keith, C., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lenisa, P., Livingston, K., Lu, H. Y., MacGregor, I . J. D., Markov, N., Mayee, M., McKinnon, B., Meekins, D., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Movsisyan, A, Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Peng, P., Phillips, J. J., Pierce, J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Rimal, D., Ripani, M., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Sharabian, Y. G., Simonyan, A., Smith, C., Smith, G., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sytnik, V., Taiuti, M., Tang, W., Tkachenko, S., Ungaro, M., Vernarsky, B ., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D . P., Weinstein, L. B., Zachariou, N., Zana, L., Zhang, J., Zhao, B., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

The inclusive polarized structure functions of the proton and deuteron, g1p and g1d, were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory. Electrons scattered at lab angles between 18 and 45 degrees were detected using the CEBAF Large Acceptance Spectrometer (CLAS). For the usual DIS kinematics, Q^2>1 GeV^2 and the final-state invariant mass W>2 GeV, the ratio of polarized to unpolarized structure functions g1/F1 is found to be nearly independent of Q^2 at fixed x. Significant resonant structure is apparent at values of W up to 2.3 GeV. In the framework of perturbative QCD, the high-W results can be used to better constrain the polarization of quarks and gluons in the nucleon, as well as high-twist contributions.

Published
2014
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5. Demonstration of a novel technique to measure two-photon exchange effects in elastic $e^\pm p$ scattering

Author

Moteabbed, M., Niroula, M., Raue, B. A., Weinstein, L. B., Adikaram, D., Arrington, J., Brooks, W. K., Lachniet, J., Rimal, Dipak, Ungaro, M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Pereira, S. Anefalos, Avakian, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bennett, R. P., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Cole, P. L., Collins, P., Contalbrigo, M., Cortes, O., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Lewis, S., Lu, H. Y., MacCormick, M., MacGregor, I . J . D., Martinez, D., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moriya, K., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S., Strauch, S., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Voskanyan, H., Voutier, E., Walford, N. K., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations of TPE corrections have significant model dependence, and there is limited direct experimental evidence for such corrections. We present the results of a new experimental technique for making direct $e^\pm p$ comparisons, which has the potential to make precise measurements over a broad range in $Q^2$ and scattering angles. We use the Jefferson Lab electron beam and the Hall B photon tagger to generate a clean but untagged photon beam. The photon beam impinges on a converter foil to generate a mixed beam of electrons, positrons, and photons. A chicane is used to separate and recombine the electron and positron beams while the photon beam is stopped by a photon blocker. This provides a combined electron and positron beam, with energies from 0.5 to 3.2 GeV, which impinges on a liquid hydrogen target. The large acceptance CLAS detector is used to identify and reconstruct elastic scattering events, determining both the initial lepton energy and the sign of the scattered lepton. The data were collected in two days with a primary electron beam energy of only 3.3 GeV, limiting the data from this run to smaller values of $Q^2$ and scattering angle. Nonetheless, this measurement yields a data sample for $e^\pm p$ with statistics comparable to those of the best previous measurements. We have shown that we can cleanly identify elastic scattering events and correct for the difference in acceptance for electron and positron scattering. The final ratio of positron to electron scattering: $R=1.027\pm0.005\pm0.05$ for $=0.206$ GeV$^2$ and $0.830\leq \epsilon\leq 0.943$.

Published
2013
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6. Hard Two-body Photodisintegration of 3He

Author

Pomerantz, I., Ilieva, Y., Gilman, R., Higinbotham, D. W., Piasetzky, E., Strauch, S., Adhikari, K. P., Aghasyan, M., Allada, K., Amaryan, M. J., Pereira, S. Anefalos, Anghinolfi, M., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Beck, A., Beck, S., Bedlinskiy, I., Berman, B. L., Biselli, A. S., Boeglin, W., Bono, J., Bookwalter, C., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bubis, N., Burkert, V., Camsonne, A., Canan, M., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chirapatpimol, K., Cisbani, E., Cole, P. L., Contalbrigo, M., Crede, V., Cusanno, F., D'Angelo, A., Daniel, A., Dashyan, N., de Jager, C. W., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Dutta, C., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Fradi, A., Garibaldi, F., Geagla, O., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Glister, J., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jiang, X., Jo, H. S., Joo, K., Katramatou, A. T., Keller, D., Khandaker, M., Khetarpal, P., Khrosinkova, E., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuleshov, S. V., Kvaltine, N. D., Lee, B., LeRose, J. J., Lewis, S., Lindgren, R., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Martinez, D., Mayer, M., McCullough, E., McKinnon, B., Meekins, D., Meyer, C. A., Michaels, R., Mineeva, T., Mirazita, M., Moffit, B., Mokeev, V., Montgomery, R. A., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., Nepali, C. S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Petratos, G. G., Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Procureur, S., Protopopescu, D., Puckett, A. J. R., Qian, X., Qiang, Y., Ricco, G., Rimal, D., Ripani, M., Ritchie, B. G., Rodriguez, I., Ron, G., Rosner, G., Rossi, P., Sabatie, F., Saha, A., Saini, M. S., Sarty, A. J., Sawatzky, B., Saylor, N. A., Schott, D., Schulte, E., Schumacher, R. A., Seder, E., Seraydaryan, H., Shneor, R., Smith, G. D., Sokhan, D., Sparveris, N., Stepanyan, S. S., Stepanyan, S., Stoler, P., Subedi, R., Sulkosky, V., Taiuti, M., Tang, W., Taylor, C. E., Tkachenko, S., Ungaro, M., Vernarsky, B., Vineyard, M. F., Voskanyan, H., Voutier, E., Walford, N. K., Wang, Y., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wojtsekhowski, B., Wood, M. H., Yan, X., Yao, H., Zachariou, N., Zhan, X., Zhang, J., Zhao, Z. W., Zheng, X., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

We have measured cross sections for the gamma+3He->p+d reaction at photon energies of 0.4 - 1.4 GeV and a center-of-mass angle of 90 deg. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.

Published
2013
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7. Transverse Polarization of $\Sigma^{+}(1189)$ in Photoproduction on a Hydrogen Target in CLAS

Author

Nepali, C. S., Amaryan, M., Adhikari, K. P., Aghasyan, M., Pereira, S. Anefalos, Baghdasaryan, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Collins, P., Contalbrigo, M., Crede, V., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Alaoui, A. El, Fassi, L. El, Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Gabrielyan, M. Y., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Koirala, S., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McKinnon, B., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Rimal, D., Ripani, M., Ritchie, B. G., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Torayev, B., Vernarsky, B., Vlassov, A. V., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Zachariou, N., Zana, L., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

Experimental results on the $\Sigma^+(1189)$ hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson laboratory are presented. The $\Sigma^+(1189)$ was reconstructed in the exclusive reaction $\gamma+p\rightarrow K^{0}_{S} + \Sigma^+(1189)$ via the $\Sigma^{+} \to p \pi^{0}$ decay mode. The $K^{0}_S$ was reconstructed in the invariant mass of two oppositely charged pions with the $\pi^0$ identified in the missing mass of the detected $p\pi^+\pi^-$ final state. Experimental data were collected in the photon energy range $E_{\gamma}$ = 1.0-3.5 GeV ($\sqrt{s}$ range 1.66-2.73 GeV). We observe a large negative polarization of up to 95%. As the mechanism of transverse polarization of hyperons produced in unpolarized photoproduction experiments is still not well understood, these results will help to distinguish between different theoretical models on hyperon production and provide valuable information for the searches of missing baryon resonances., Comment: pages 11

Published
2013
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8. Near Threshold Neutral Pion Electroproduction at High Momentum Transfers and Generalized Form Factors

Author

Khetarpal, P., Stoler, P., Aznauryan, I. G., Kubarovsky, V., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anderson, M. D., Pereira, S. Anefalos, Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bono, J., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Charles, G., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Fleming, J. A., Fradi, A., Gabrielyan, M. Y., Garçon, M., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hicks, K., Ho, D., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kuleshov, S. V., Kvaltine, N. D., Lewis, S., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Phelps, E., Phillips, J. J., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Saylor, N. A., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tkachenko, S., Ungaro, M., Vernarsky, B., Voskanyan, H., Voutier, E., Walford, N. K., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

We report the measurement of near threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range $Q^2$ from 2 to 4.5 GeV$^2$ and $W$ from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles $E_{0+}$ and $S_{0+}$ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors $G_1^{\pi^0 p}(Q^2)$ and $G_2^{\pi^0 p}(Q^2)$. The data are compared to these generalized form factors and the results for $G_1^{\pi^0 p}(Q^2)$ are found to be in good agreement with the LCSR predictions, but the level of agreement with $G_2^{\pi^0 p}(Q^2)$ is poor., Comment: 17 pages, 18 figures, Journal article (Physical Review C)

Published
2012
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9. Measurement of Exclusive $\pi^0$ Electroproduction Structure Functions and their Relationship to Transversity GPDs

Author

CLAS Collaboration, Bedlinskiy, I., Kubarovsky, V., Niccolai, S., Stoler, P., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bennett, R. P., Biselli, A. S., Bookwalter, C., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Garçon, M., Gevorgyan, N., Giovanetti, K. L., Girod, F. X., Gohn, W., Gothe, R. W., Graham, L., Griffioen, K. A., Guegan, B., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kuhn, S. E., Kuleshov, S. V., Kvaltine, N. D., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Markov, N., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Saylor, N., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Ungaro, M., Vineyard, M. F., Vlassov, A., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

Exclusive $\pi^0$ electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were measured at more than 1800 kinematic values in $Q^2$, $x_B$, $t$, and $\phi_\pi$, in the $Q^2$ range from 1.0 to 4.6 GeV$^2$,\ $-t$ up to 2 GeV$^2$, and $x_B$ from 0.1 to 0.58. Structure functions $\sigma_T +\epsilon \sigma_L, \sigma_{TT}$ and $\sigma_{LT}$ were extracted as functions of $t$ for each of 17 combinations of $Q^2$ and $x_B$. The data were compared directly with two handbag-based calculations including both longitudinal and transversity GPDs. Inclusion of only longitudinal GPDs very strongly underestimates $\sigma_T +\epsilon \sigma_L$ and fails to account for $\sigma_{TT}$ and $\sigma_{LT}$, while inclusion of transversity GPDs brings the calculations into substantially better agreement with the data. There is very strong sensitivity to the relative contributions of nucleon helicity flip and helicity non-flip processes. The results confirm that exclusive $\pi^0$ electroproduction offers direct experimental access to the transversity GPDs., Comment: 6 pages, 2 figures

Published
2012
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10. Deep exclusive $\pi^+$ electroproduction off the proton at CLAS

Author

Park, K., Guidal, M., Gothe, R. W., Laget, J. M., Garçon, M., Adhikari, K. P., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Avakian, H., Baghdasaryan, H., Ball, J., Baltzell, N. A., Battaglieri, M., Bedlinsky, I., Bennett, R. P., Biselli, A. S., Bookwalter, C., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Fradi, A., Eugenio, P., Fedotov, G., Fegan, S., Fleming, J. A., Forest, T. A., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Graham, L., Griffioen, K. A., Guegan, B., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Heddle, D., Hicks, K., Ho, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Jenkins, D., Jo, H. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, F. J., Koirala, S., Kubarovsky, A., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Livingston, K., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Markov, N., Martinez, D., Mayer, M., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moutarde, H., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Nepali, C. S., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Puckett, A. J. R., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatie, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tian, Ye, Tkachenko, S., Trivedi, A., Ungaro, M., Vernarsky, B ., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.

Subjects
Nuclear Experiment
Abstract

The exclusive electroproduction of $\pi^+$ above the resonance region was studied using the $\rm{CEBAF}$ Large Acceptance Spectrometer ($\rm{CLAS}$) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of $\rm{CLAS}$, together with the high luminosity, allowed us to measure the cross section for the $\gamma^* p \to n \pi^+$ process in 140 ($Q^2$, $x_B$, $t$) bins: $0.16

Published
2012
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11. Evidence for the Onset of Color Transparency in $\rho^0$ Electroproduction off Nuclei

Author

Fassi, L. El, Zana, L., Hafidi, K., Holtrop, M., Mustapha, B., Brooks, W. K., Hakobyan, H., Zheng, X., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anghinolfi, M., Arrington, J., Avakian, H., Baghdasaryan, H., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Bookwalter, C., Branford, D., Briscoe, W. J., Bultmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Dey, B., Dickson, R., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Gabrielyan, M. Y., Garcon, M., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hanretty, C., Heddle, D., Hicks, K., Holt, R. J., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jawalkar, S. S., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kuznetsov, V., Laget, J. M., Lu, H. Y., MacGregor, I. J. D., Mao, Y., Markov, N., Mayer, M., McAndrew, J., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moreno, B., Moutarde, H., Munevar, E., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Pappalardo, L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Raue, B. A., Reimer, P. E., Ricco, G., Rimal, D., Ripani, M., Ritchie, B. G., Rosner, G., Rossi, P., Sabatie, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Stoler, P., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tedeschi, D. J., Tkachenko, S., Ungaro, M., Vernarsky, B ., Vineyard, M. F., Voskanyan, H., Voutier, E., Watts, D., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zhao, B., and Zhao, Z. W.

Subjects
Nuclear Experiment
Abstract

We have measured the nuclear transparency of the incoherent diffractive $A(e,e'\rho^0)$ process in $^{12}$C and $^{56}$Fe targets relative to $^2$H using a 5 GeV electron beam. The nuclear transparency, the ratio of the produced $\rho^0$'s on a nucleus relative to deuterium, which is sensitive to $\rho A$ interaction, was studied as function of the coherence length ($l_c$), a lifetime of the hadronic fluctuation of the virtual photon, and the four-momentum transfer squared ($Q^2$). While the transparency for both $^{12}$C and $^{56}$Fe showed no $l_c$ dependence, a significant $Q^2$ dependence was measured, which is consistent with calculations that included the color transparency effects., Comment: 6 pages and 4 figures

Published
2012
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12. Measurement of the neutron F2 structure function via spectator tagging with CLAS

Author

Baillie, N., Tkachenko, S., Zhang, J., Bosted, P., Bultmann, S., Christy, M. E., Fenker, H., Griffioen, K. A., Keppel, C. E., Kuhn, S. E., Melnitchouk, W., Tvaskis, V., Adhikari, K. P., Adikaram, D., Aghasyan, M., Amaryan, M. J., Anghinolfini, M., Arrington, J., Avakian, H., Baghdasaryan, H., Battaglieri, M., Biselli, A. S., Branford, 5 D., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Dey, B., Djalali, C., Dodge, G., Domingo, J., Doughty, D., Dupre, R., Dutta, D., Ent, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fradi, A., Gabrielyan, M. Y., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Gothe, R. W., Graham, L., Guegan, B., Guidal, M., Guler, N., Guo, L., Hafidi, K., Heddle, D., Hicks, K., Holtrop, M., Hungerford, E., Hyde, C. E., Ilieva, Y., Ireland, D. G., Ispiryan, M., Isupov, E. L., Jawalkar, S. S., Jo, H. S., Kalantarians, N., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., King, P. M., Klein, A., Klein, F. J., Klimenko, A., Kubarovsky, V., Kuleshov, S. V., Kvaltine, N. D., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Mao, Y., Markov, N., McKinnon, B., Mineeva, T., Morrison, B., Moutarde, H., Munevar, E., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, I., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Pappalardo, L., Park, K., Park, S., Pasyuk, E., Pereira, S. Anefalos, Pisano, S., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Rossi, P., Sabatie, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Sharabian, Y. G., Sober, D. I., Sokhan, D., Stepanyan, S., Stepanyan, S. S., Stoler, P., Strauch, S., Taiuti, M., Tang, W., Ungaro, M., Vineyard, M. F., Voutier, E., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zana, L., and Zhao, B.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report on the first measurement of the F2 structure function of the neutron from semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to < 100 MeV and their angles to < 100 degrees relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F2n data collected cover the nucleon resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65 < Q2 < 4.52 GeV2, with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F2n/F2p at 0.2 < x < 0.8 with little uncertainty due to nuclear effects., Comment: 6 pages, 3 pages

Published
2011
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13. Precise Measurements of Beam Spin Asymmetries in Semi-Inclusive $\pi^0$ production

Author

Aghasyan, M., Avakian, H., Rossi, P., De Sanctis, E., Hasch, D., Mirazita, M., Adikaram, D., Amaryan, M. J., Anghinolfi, M., Baghdasaryan, H., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bennett, R. P., Biselli, A. S., Branford, D., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Chandavar, S., Cole, P. L., Collins, P., Contalbrigo, M., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., Deur, A., Dey, B., Dickson, R., Djalali, C., Dodge, G. E., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fradi, A., Gabrielyan, M. Y., Garçon, M., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Golovatch, E., Gothe, R. W., Graham, L., Griffioen, K. A., Guegan, B., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hanretty, C., Hicks, K., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jawalkar, S. S., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kimy, W., Klein, A., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kuznetsov, V., Kvaltine, N. D., Livingston, K., Lu, H. Y., MacGregor, I . J . D., Markov, N., Mayer, M., McAndrew, J., McKinnon, B., Meyer, C. A., Micherdzinska, A. M., Mokeev, V., Moreno, B., Moutarde, H., Munevar, E., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Pereira, S. Anefalos, Phelps, E., Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ricco, G., Rimal, D., Ripani, M., Rosner, G., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, G. D., Sober, D. I., Stepanyan, S. S., Stepanyan, S., Stoler, P., Strakovsky, I., Strauch, S., Taiuti, M., Tang, W., Taylor, C. E., Tkachenko, S., Ungaro, M., Voskanyan, H., Voutier, E., Watts, D., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zana, L., Zhang, J., Zhao, B., and Zhao, Z. W.

Subjects
High Energy Physics - Experiment
Abstract

We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial $\sin \phi_h$ amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle $\phi_h$ of the produced neutral pion. The dependence of this amplitude on Bjorken $x$ and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations., Comment: to be submitted PLB

Published
2011
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14. Near-threshold Photoproduction of Phi Mesons from Deuterium

Author

Qian, X., Chen, W., Gao, H., Hicks, K., Kramer, K., Laget, J. M., Mibe, T., Qiang, Y., Stepanyan, S., Tedeschi, D. J., Xu, W., Adhikari, K. P., Amaryan, M., Anghinolfi, M., Ball, J., Battaglieri, M., Batourine, V., Bedlinskiy, I., Bellis, M., Biselli, A. S., Bookwalter, C., Branford, D., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Careccia, S. L., Carman, D. S., Cole, P. L., Collins, P., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Dey, B., Dhamija, S., Djalali, C., Doughty, D., Dupre, R., Egiyan, H., Alaoui, A. El, Eugenio, P., Fegan, S., Gabrielyan, M. Y., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J. T., Gohn, W., Gothe, R. W., Graham, L., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Hassall, N., Holtrop, M., Ilieva, Y., Ireland, D. G., Jawalkar, S. S., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Khetarpal, P., Kim, A., Kim, W., Klein, A., Klein, F. J., Konczykowski, P., Kubarovsky, V., Kuleshov, S. V., Kuznetsov, V., Livingston, K., Martinez, D., Mayer, M., McAndrew, J., McCracken, M. E., McKinnon, B., Meyer, C. A., Mikhailov, K., Mineeva, T., Mirazita, M., Mokeev, V., Moreno, B., Moriya, K., Morrison, B., Moutarde, H., Munevar, E., Nadel-Turonski, P., Ni, A., Niccolai, S., Niculescu, I., Niroula, M. R., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Park, S., Pereira, S. Anefalos, Pisano, S., Pogorelko, O., Pozdniakov, S., Price, J. W., Procureur, S., Protopopescu, D., Ricco, G., Ripani, M., Ritchie, B. G., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salgado, C., Schott, D., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Smith, E. S., Smith, G. D., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Taylor, C. E., Tkachenko, S., Ungaro, M., Vernarsky, B ., Vineyard, M. F., Voutier, E., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zachariou, N., Zana, L., Zhang, J., Zhao, B., and Zhao, Z. W.

Subjects
Nuclear Experiment
Abstract

We report the first measurement of the differential cross section on $\phi$-meson photoproduction from deuterium near the production threshold for a proton using the CLAS detector and a tagged-photon beam in Hall B at Jefferson Lab. The measurement was carried out by a triple coincidence detection of a proton, $K^+$ and $K^-$ near the theoretical production threshold of 1.57 GeV. The extracted differential cross sections $\frac{d\sigma}{dt}$ for the initial photon energy from 1.65-1.75 GeV are consistent with predictions based on a quasifree mechanism. This experiment establishes a baseline for a future experimental search for an exotic $\phi$-N bound state from heavier nuclear targets utilizing subthreshold/near-threshold production of $\phi$ mesons.

Published
2010
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15. Measurement of Single and Double Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

Author

The CLAS Collaboration, Avakian, H., Bosted, P., Burkert, V. D., Elouadrhiri, L., Adhikari, K. P., Aghasyan, M., Amaryan, M., Anghinolfi, M., Baghdasaryan, H., Ball, J., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Branford, D., Briscoe, W. J., Brooks, W., Carman, D. S., Casey, L., Cole, P. L., Collins, P., Crabb, D., Crede, V., D'Angelo, A., Daniel, A., Dashyan, N., DeVita, R., DeSanctis, E., Deur, A., Dey, B., Dhamija, S., Dickson, R., Djalali, C., Dodge, G., Doughty, D., Dupre, R., ElAlaoui, A., Eugenio, P., Fegan, S., Fersch, R., Forest, T. A., Fradi, A., Gabrielyan, M. Y., Gavalian, G., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gohn, W., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Hassall, N., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jawalkar, S. S., Jo, H. S., Joo, K., Keller, D., Khandaker, M., Khetarpal, P., Kim, W., Klein, A., Klein, F. J., Konczykowski, P., Kubarovsky, V., Kuhn, S. E., Kuleshov, S. V., Kuznetsov, V., Livingston, K., Lu, H. Y., Markov, N., Mayer, M., McAndrew, J., McCracken, M. E., McKinnon, B., Meyer, C. A., Mineeva, T., Mirazita, M., Mokeev, V., Moreno, B., Moriya, K., Morrison, B., Moutarde, H., Munevar, E., Nadel-Turonski, P., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Niroula, M. R., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Park, S., Pasyuk, E., Pereira, S. Anefalos, Perrin, Y., Pisano, S., Pogorelko, O., Price, J. W., Procureur, S., Prok, Y., Protopopescu, D., Raue, B. A., Ricco, G., Ripani, M., Rosner, G., Rossi, P., Sabatié, F., Saini, M. S., Salamanca, J., Salgado, C., Schumacher, R. A., Seder, E., Seraydaryan, H., Sharabian, Y. G., Sober, D. I., Sokhan, D., Stepanyan, S. S., Stepanyan, S., Stoler, P., Strauch, S., Suleiman, R., Taiuti, M., Tedeschi, D. J., Tkachenko, S., Ungaro, M., Vernarsky, B ., Vineyard, M. F., Voutier, E., Watts, D. P., Weinstein, L. B., Weygand, D. P., Wood, M. H., Zhang, J., Zhao, B., and Zhao, Z. W.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report the first measurement of the transverse momentum dependence of double spin asymmetries in semi-inclusive production of pions in deep inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Thomas Jefferson National Accelerator Facility (JLab). A significant non-zero $\sin2\phi$ single spin asymmetry was also observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. The azimuthal modulations of single spin asymmetries have been measured over a wide kinematic range.

Published
2010
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