Leptoproduction of $\rho$-mesons as discriminator for the unintegrated gluon distribution in the proton

TL;DR

This paper explores how polarized rho-meson leptoproduction at HERA can serve as a sensitive test to distinguish between different models of the unintegrated gluon distribution in the proton, which is crucial for understanding high-energy gluon dynamics.

Contribution

It demonstrates that polarized rho-meson leptoproduction provides a novel and effective way to discriminate among various models of the unintegrated gluon distribution within the proton.

Findings

Polarized rho-meson leptoproduction is sensitive to UGD models.

Different UGD models produce distinguishable predictions.

The approach offers a new testing ground for gluon distribution models.

Abstract

The gluon content of the proton, in the high-energy regime, is embodied by the unintegrated gluon distribution (UGD), which describes the gluon emission probability, with a given longitudinal momentum fraction and transverse momentum. The UGD, formulated within the $\kappa$-factorization approach, has universal validity and several models for it have been proposed so far. We will show that the polarized $\rho$-meson leptoproduction at HERA is a not trivial testfield for discriminating among existing models of UGD.