Exclusive emissions of polarized $\rho$ mesons at the EIC and the proton content at low $x$

TL;DR

This paper investigates the exclusive production of polarized rho mesons at the EIC, using high-energy factorization to explore how polarization-sensitive observables can differentiate UGD models and reveal proton structure at low x.

Contribution

It introduces a new framework for analyzing polarized rho meson production at the EIC, linking helicity amplitudes with UGD models to probe proton content at low x.

Findings

Polarization observables can discriminate between different UGD models.

The study provides quantitative insights into proton structure at high energies.

The convolution approach links impact factors with the UGD evolution.

Abstract

We present a new study on helicity amplitudes and cross sections for the exclusive production of $\rho$ mesons at the EIC in high-energy factorization. In this framework the analytic expression of amplitudes takes the form of a convolution between an off-shell impact factor, depicting the ($\gamma^* \to \rho$) transition, and a nonperturbative density, known as Unintegrated Gluon Distribution (UGD) that encodes information about the proton structure at low $x$ and evolves according to the BFKL equation. We come out with an evidence that observables sensitive to the polarizations of the incoming virtual photon and of the emitted meson allow us to discriminate among different UGD models and to gather quantitative information on the proton content at high energies.