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Charged pion form factor between Q 2 = 0 . 60 and 2 . 45 GeV <mml:msup…

2008; American Institute of Physics; Volume: 78; Issue: 4 Linguagem: Inglês

10.1103/physrevc.78.045203

1538-4497

G. M. Huber, H. P. Blok, T. Horn, E. J. Beise, D. Gaskell, D. Mack, V. Tadevosyan, J. Volmer, D. Abbott, K. Aniol, H. Anklin, Christopher Armstrong, J. Arrington, K. Assamagan, S. Avery, O. K. Baker, B. Barrett, C. Bochna, W. Boeglin, E. J. Brash, H. Breuer, C. C. Chang, N. S. Chant, M. E. Christy, J. Dunne, T. Eden, R. Ent, H. Fenker, E. F. Gibson, R. Gilman, K. Gustafsson, W. Hinton, R. J. Holt, H. E. Jackson, Shan Jin, M. Jones, C. Keppel, P. H. Kim, W. Kim, P. M. King, A. Klein, D. Koltenuk, V. Kovaltchouk, M. Liang, J. Liu, G. J. Lolos, A. Lung, D. J. Margaziotis, P. Markowitz, Akihiko Matsumura, D. McKee, D. Meekins, Jason W. Mitchell, T. Miyoshi, H. Mkrtchyan, B. Mueller, G. Niculescu, I. Niculescu, Y. Okayasu, L. Pentchev, C. F. Perdrisat, D. Pitz, D. H. Potterveld, V. Punjabi, L. M. Qin, P. E. Reimer, J. Reinhold, J. Roche, P. G. Roos, A. Sarty, I. K. Shin, G. R. Smith, S. Stepanyan, L. Tang, V. Tvaskis, R. L. J. van der Meer, K. Vansyoc, Derek van Westrum, S. Vidakovic, W. Vulcan, G. Warren, S. A. Wood, Chang Xu, Chao Yan, W. Zhao, Xiaochao Zheng, B. Zihlmann,

High-Energy Particle Collisions Research

The charged pion form factor, ${F}_{\ensuremath{\pi}}({Q}^{2})$, is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction of ${F}_{\ensuremath{\pi}}$ from data requires a model of the ${}^{1}\mathrm{H}(e,{e}^{'}{\ensuremath{\pi}}^{+})n$ reaction and thus is inherently model dependent. Therefore, a detailed description of the extraction of the charged pion form factor from electroproduction data obtained recently at Jefferson Lab is presented, with particular focus given to the dominant uncertainties in this procedure. Results for ${F}_{\ensuremath{\pi}}$ are presented for ${Q}^{2}=0.60\text{\ensuremath{-}}2.45 {\mathrm{GeV}}^{2}$. Above ${Q}^{2}=1.5 {\mathrm{GeV}}^{2}$, the ${F}_{\ensuremath{\pi}}$ values are systematically below the monopole parametrization that describes the low ${Q}^{2}$ data used to determine the pion charge radius. The pion form factor can be calculated in a wide variety of theoretical approaches, and the experimental results are compared to a number of calculations. This comparison is helpful in understanding the role of soft versus hard contributions to hadronic structure in the intermediate ${Q}^{2}$ regime.