Exclusive π+ electroproduction off the proton from low to high -t

Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies.

Purpose: To study the transition between nonperturbative and perturbative quantum chromodynamics as the square of four-momentum transfer to the struck proton, -t , is increased.

Method: Cross sections for the ¹H(e ,e^'π⁺) n reaction were measured over the -t range of 0.272 to 2.127 GeV² with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q² of 2.4 GeV², and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C.

Results: The -t dependence of the measured π⁺ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude-based theoretical model but show poor agreement with a generalized parton distribution-based model.

Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t slopes between the low- and high-t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime.