Beam spin asymmetry in deeply virtual $\pi$ production

TL;DR

This paper presents a model combining Regge pole and nucleon resonance effects to interpret beam spin asymmetries in deeply virtual pion production, aligning well with JLAB data.

Contribution

It introduces a novel combined approach using Regge theory and nucleon resonances to explain azimuthal asymmetries in exclusive pion electroproduction.

Findings

Model agrees with experimental data when nucleon resonance excitations are included.

Dual Bloom-Gilman connection effectively links exclusive form factors with inclusive structure functions.

Incorporating nucleon resonances is essential for accurate asymmetry predictions.

Abstract

An interpretation of the beam spin azimuthal asymmetries measured at JLAB in deep exclusive electroproduction of charged and neutral pions is presented. The model combines a Regge pole approach with the effect of nucleon resonances. The $s$- and $u$-channel contributions are described using a dual Bloom-Gilman connection between the exclusive form factors and inclusive deep inelastic structure functions. The results are in agreement with data provided the excitations of nucleon resonances are taken into account.