Exclusive pi^+ production at HERMES

TL;DR

This paper reports on measurements of exclusive pi^+ production at HERMES, providing insights into the nucleon's Generalized Parton Distributions through cross section and asymmetry data.

Contribution

First preliminary results for unpolarized cross sections and single-spin asymmetries in exclusive pi^+ production at HERMES are presented and compared to GPD models.

Findings

Unpolarized cross section measurements for 1.5<Q^2<10.5 GeV^2 and 0.02<x<0.8.

First results for single-spin asymmetry with a longitudinal polarized target.

Comparison of experimental data with GPD calculations.

Abstract

Hard exclusive production in deep inelastic lepton scattering provides access to the unknown Generalized Parton Distributions (GPDs) of the nucleon. At HERMES, different observables for hard exclusive pi^+ production have been measured with a 27.6 GeV positron beam on an internal hydrogen gas target. First preliminary results for the unpolarized ep->enpi^+ total cross section for 1.5<Q^2<10.5 GeV^2 and for 0.02<x<0.8 are presented and compared to GPD calculations. The final result for the single-spin asymmetry using a longitudinal polarized target is also reported.