On high energy exclusive leptoproduction of the rho meson up to twist 3

TL;DR

This paper presents a phenomenological study of high-energy exclusive leptoproduction of the rho meson, incorporating twist 3 distribution amplitudes within a Regge-inspired k_T-factorization framework, achieving good agreement with experimental data.

Contribution

It introduces a consistent application of twist 3 distribution amplitudes in the impact factor calculations for rho meson production within a Regge-inspired scheme.

Findings

Results agree with high-energy experimental data

Impact factors computed up to twist 3 level

Good description of helicity amplitude ratios

Abstract

The Regge inspired k_T-factorization scheme expresses the scattering amplitude for exclusive leptoproduction of a light vector meson rho in terms of two impact factors, one for the gamma* - rho transition and the other one for the nucleon to nucleon transition, with, at leading order, a two "reggeized" gluon exchange in the t-channel. We report here on a recent phenomenological study where we apply a previously developped scheme which consistently takes into account the twist 3 distribution amplitudes for transversely polarized rho meson. The computation of the gamma* to rho impact factor are performed within collinear factorization of QCD, up to the twist 3 level, based on the Collinear Factorization scheme applied to the amplitudes gamma*g to g rho . Our results are in good agreement with high energy experimental data for the ratios of helicity amplitudes.