Role of the {rho} meson in the description of pion electroproduction experiments
- Institut fuer Theoretische Physik, Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)
- Institute of Nuclear Physics, Moscow State University, RU-119899 Moscow (Russian Federation)
We study the p(e,e{sup '}{pi}{sup +})n reaction in the framework of an effective Lagrangian approach including nucleon, {pi} and {rho} meson degrees of freedom and show the importance of the {rho}-meson t-pole contribution to {sigma}{sub T}, the transverse part of cross section. We test two different field representations of the {rho} meson, vector and tensor, and find that the tensor representation of the {rho} meson is more reliable in the description of the existing data. In particular, we show that the {rho}-meson t-pole contribution, including the interference with an effective nonlocal contact term, sufficiently improves the description of the recent JLab data at invariant mass W < or approx. 2.2 GeV and Q{sup 2} < or approx. 2.5 GeV{sup 2}/c{sup 2}. A 'soft' variant of the strong {pi}NN and {rho}NN form factors is also found to be compatible with these data. On the basis of the successful description of both the {sigma}{sub L} and {sigma}{sub T} parts of the cross section we discuss the importance of taking into account the {sigma}{sub T} data when extracting the charge pion form factor F{sub {pi}} from {sigma}{sub L}.
- OSTI ID:
- 21062002
- Journal Information:
- Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 76; ISSN 0556-2813; ISSN PRVCAN
- Country of Publication:
- United States
- Language:
- English
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