Charged pion electroproduction above the resonance region
Abstract
[Background] Above the nucleon resonance region, the data cannot be explained by conventional hadronic models. For example, the observed magnitude of the transverse cross section is significantly underestimated in a framework with Reggeized background amplitudes. [Purpose] Develop a phenomenological framework for the reaction at high invariant mass and deep photon virtuality . [Method] Building on the work of Kaskulov and Mosel, a gauged pion-exchange current is introduced with a running cutoff energy for the proton electromagnetic transition form factor. A new transition form factor is proposed. It respects the correct on-shell limit, has a simple physical interpretation and reduces the number of free parameters by one. [Results] A study of the dependence of the lends support for the newly proposed transition form factor. In addition, an improved description of the separated and unseparated cross sections at is obtained. The predictions overshoot the measured unseparated cross sections for . Introducing a strong hadronic form factor in the Reggeized background amplitudes brings the calculations considerably closer to the high data. [Conclusions] Hadronic models corrected for resonance/parton duality describe the separated pion electroproduction cross sections above the resonance region reasonably well at low . In order to validate the applicability of these models at high , separated cross sections are needed. These are expected to provide a more profound insight into the relevant reaction mechanisms.
Keywords
Cite
@article{arxiv.1310.7715,
title = {Charged pion electroproduction above the resonance region},
author = {Tom Vrancx and Jan Ryckebusch},
journal= {arXiv preprint arXiv:1310.7715},
year = {2014}
}
Comments
11 pages, 8 figures