Measurement of Target and Double-spin Asymmetries for the $\vec e\vec p\to e\pi^+ (n)$ Reaction in the Nucleon Resonance Region at Low $Q^2$

Autor: Zheng, X., Adhikari, K. P., Bosted, P., Deur, A., Drozdov, V., Fassi, L. El, Kang, Hyekoo, Kovacs, K., Kuhn, S., Long, E., Phillips, S. K., Ripani, M., Slifer, K., Smith, L. C., Adikaram, D., Akbar, Z., Amaryan, M. J., Pereira, S. Anefalos, Asryan, G., Avakian, H., Badui, R. A., Ball, J., Baltzell, N. A., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Bültmann, S., Burkert, V. D., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chen, J. -P., Chetry, T., Choi, Seonho, Ciullo, G., Clark, L., Colaneri, L., Cole, P. L., Compton, N., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Djalali, C., Dodge, G. E., Dupre, R., Egiyan, H., Alaoui, A. El, Elouadrhiri, L., Eugenio, P., Fanchini, E., Fedotov, G., Fersch, R., Filippi, A., Fleming, J. A., Gevorgyan, N., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Gleason, C., Golovach, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hanretty, C., Harrison, N., Hattawy, M., Hicks, K., Holtrop, M., Hughes, S. M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jiang, H., Jo, H. S., Joosten, S., Keller, D., Khachatryan, G., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I . J . D., Markov, N., McKinnon, B., Mirazita, M., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Murdoch, G., Nadel-Turonski, P., Net, L. A., Ni, A., Niccolai, S., Niculescu, G., Niculescu, I., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Peng, P., Pisano, S., Pogorelko, O., Price, J. W., Puckett, A. J. R., Raue, B. A., Rizzo, A., Rosner, G., Rossi, P., Roy, P., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sokhan, D., Sparveris, N., Stankovic, I., Strakovsky, I. I., Strauch, S., Taiuti, M., Tian, Ye, Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zhang, J.
Rok vydání: 2016
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevC.94.045206
Popis: We report measurements of target- and double-spin asymmetries for the exclusive channel $\vec e\vec p\to e\pi^+ (n)$ in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH$_3$ target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3 and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low $Q^2$ range from $0.0065$ to $0.35$ (GeV$/c$)$^2$. The $Q^2$ access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as $6^\circ$. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models.
Comment: 20 pages, 15 figures, to appear in Phys. Rev. C
Databáze: arXiv