Inelastic $J/\psi$ production in polarized photon-hadron collisions

TL;DR

This paper calculates inelastic $J/ar{J}$ production in polarized photon-hadron collisions using NRQCD, offering new tests for the color-octet mechanism and insights into polarized gluon distributions at HERA energies.

Contribution

It provides a theoretical framework for inelastic $J/ar{J}$ production in polarized collisions, highlighting its potential to test the color-octet mechanism and distinguish polarized gluon distributions.

Findings

The process can serve as an independent test for the color-octet mechanism.

Different features of the two color-octet processes are identified.

Discrepancies in production asymmetry $A$ are sensitive to polarized gluon distributions.

Abstract

Presented here is a calculation of inelastic $J/\psi$ production in polarized photon-hadron collisions under the framework of NRQCD factorization formalism. We consider the photoproduction of $\jpsi$ in the energy range relevant to HERA. The Weizs\"acker-Williams approximation is adopted in the evaluation of the cross sections for $ep$ collisions. We found that this process can give another independent test for the color-octet mechanism, and the different features for the two color-octet processes may provide further informations on the mechanism for inelastic $\jpsi$ photoproduction. And the discrepancy on the production asymmetry $A$ between various sets of polarized gluon distribution functions is also found to be distinctive.