Determination of the pion charge form factor at Q2=1.60 and 2.45 (GeV/c)2.
/ Authors
T. Horn, R. Holt, V. Punjabi, G. Lolos, P. King, H. Breuer, I. Niculescu, H. Mkrtchyan, J. Arrington, W. Vulcan
and 44 more authors
Y. Okayasu, H. Blok, C. Xu, D. Gaskell, G. Wood, S. Vidaković, W. Kim, P. Reimer, R. Ent, E. Gibson, D. Mack, X. Zheng, E. Beise, G. Huber, C. Perdrisat, P. Markowitz, P. Roos, L. Penchev, M. Christy, A. Sarty, S. Jin, E. Brash, T. Miyoshi, G. Smith, C. Keppel, D. Potterveld, M. Jones, B. Barrett, Charles C. Chang, J. Volmer, K. Aniol, J. Roche, V. Tvaskis, V. Tadevosyan, D. Meekins, G. Warren, L. Tang, V. Kovaltchouk, W. Boeglin, S. Wood, J. Reinhold, D. Margaziotis, J. Liu, A. Matsumura
/ Abstract
The 1H(e,e'pi+)n cross section was measured at four-momentum transfers of Q2=1.60 and 2.45 GeV2 at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F(pi)) was extracted from the data by comparing the separated longitudinal pion electroproduction cross section to a Regge model prediction in which F(pi) is a free parameter. The results indicate that the pion form factor deviates from the charge-radius constrained monopole form at these values of Q2 by one sigma, but is still far from its perturbative quantum chromodynamics prediction.
Journal: Physical review letters