Role of pion pole in hard exlusive meson leptoproduction

TL;DR

This paper investigates the role of pion pole contributions and transversity GPDs in hard exclusive meson leptoproduction, highlighting their significance in omega and rho^0 meson production and matching experimental data.

Contribution

It provides a detailed analysis of pion pole effects and transversity GPDs in meson leptoproduction, emphasizing their impact on spin observables and reaction mechanisms.

Findings

Pion pole contribution is crucial in omega production.

Effects in rho^0 channel are comparatively small.

Results agree well with HERMES experimental data.

Abstract

We consider the pion pole contribution and transversity effects determined by the $H_T$ and $\bar E_T$ Generalized Parton Distributions (GPDs) which are essential in hard pseudoscalar and vector meson leptoproduction. We investigate spin effects in the $\omega$ and $\rho^0$ reactions. It is shown that the pion pole contribution is very important in the $\omega$ production. Such effects in the $\rho^0$ channel are much smaller. Our results on spin asymmetries and spin density matrix elements in these reactions were found to be in good agreement with HERMES data.