Measurement of the Generalized Form Factors Near Threshold via γ*p→nπ+ at High Q²

Authors

K. Park
Gerard P. Gilfoyle, University of RichmondFollow
et. al.

DOI

10.1103/PhysRevC.85.035208

Abstract

We report the first extraction of the pion-nucleon multipoles near the production threshold for the nπ⁺ channel at relatively high momentum transfer (Q² up to 4.2 GeV²). The dominance of the s-wave transverse multipole (E₀₊), expected in this region, allowed us to access the generalized form factor G₁ within the light-cone sum-rule (LCSR) framework as well as the axial form factor G_A. The data analyzed in this work were collected by the nearly 4π CEBAF Large Acceptance Spectrometer (CLAS) using a 5.754-GeV electron beam on a proton target. The differential cross section and the π-N multipole E₀₊/G_D were measured using two different methods, the LCSR and a direct multipole fit. The results from the two methods are found to be consistent and almost Q² independent.

Document Type

Article

Publication Date

3-2012

Publisher Statement

Copyright © 2012 American Physical Society. This article first appeared in Physical Review C 85, no. 3 (March 2012): 035208-1-35208-15. doi:10.1103/PhysRevC.85.035208.

Please note that downloads of the article are for private/personal use only.

Recommended Citation

Park, K., R. W. Gothe, K. P. Adhikari, D. Adikaram, M. Anghinolfi, H. Baghdasaryan, J. Ball, M. Battaglieri, V. Batourine, I. Bedlinskiy, R. P. Bennett, A. S. Biselli, C. Bookwalter, S. Boiarinov, D. Branford, W. J. Briscoe, W. K. Brooks, V. D. Burkert, D. S. Carman, A. Celentano, S. Chandavar, G. Charles, P. L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, A. Daniel, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, D. Doughty, R. Dupre, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, A. Fradi, M. Y. Gabrielyan, N. Gevorgyan, G. P. Gilfoyle, K. L. Giovanetti, F. X. Girod, J. T. Goetz, W. Gohn, E. Golovatch, L. Graham, K. A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, D. Heddle, K. Hicks, M. Holtrop, C. E. Hyde, Y. Ilieva, D. G. Ireland, B. S. Ishkhanov, E. L. Isupov, D. Jenkins, H. S. Jo, K. Joo, N. Kalantarians, M. Khandaker, P. Khetarpal, A. Kim, W. Kim, A. Klein, F. J. Klein, A. Kubarovsky, V. Kubarovsky, S. E. Kuhn, S. V. Kuleshov, N. D. Kvaltine, K. Livingston, H. Y. Lu, I. J. D. MacGregor, N. Markov, M. Mayer, B. McKinnon, M. D. Mestayer, C. A. Meyer, T. Mineeva, M. Mirazita, V. Mokeev, H. Moutarde, E. Munevar, P. Nadel-Turonski, R. Nasseripour, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A. I. Ostrovidov, M. Paolone, L. Pappalardo, R. Paremuzyan, S. Park, S. Anefalos Pereira, E. Phelps, S. Pisano, O. Pogorelko, S. Pozdniakov, J. W. Price, S. Procureur, Y. Prok, G. Ricco, D. Rimal, M. Ripani, B. G. Ritchie, G. Rosner, P. Rossi, F. Sabatié, M. S. Saini, C. Salgado, D. Schott, R. A. Schumacher, H. Seraydaryan, Y. G. Sharabian, E. S. Smith, G. D. Smith, D. I. Sober, D. Sokhan, S. S. Stepanyan, S. Stepanyan, P. Stoler, I. I. Strakovsky, S. Strauch, M. Taiuti, W. Tang, C. E. Taylor, Y. Tian, S. Tkachenko, A. Trivedi, M. Ungaro, B. Vernarsky, A. V. Vlassov, E. Voutier, D. P. Watts, D. P. Weygand, M. H. Wood, N. Zachariou, B. Zhao, and Z. W. Zhao. "Measurement of the Generalized Form Factors Near Threshold via γ*p→nπ⁺ at High Q²." Physical Review C 85, no. 3 (March 2012): 035208:1-15. doi:10.1103/PhysRevC.85.035208.