On multiple gluon exchange in J/psi hadroproduction

TL;DR

This paper investigates a three-gluon exchange mechanism in J/psi hadroproduction, showing it provides significant corrections at high energies like those at the Tevatron and LHC, especially at small x.

Contribution

It introduces and calculates a three-gluon contribution to J/psi production within perturbative QCD, highlighting its importance at high energies and small x.

Findings

Three-gluon exchange significantly affects J/psi production cross-sections.

The mechanism is enhanced at small x and high energies.

Differential p_T-dependent cross-sections are provided for polarization analysis.

Abstract

We consider a contribution to J/psi hadroproduction in which the meson production is mediated by three-gluon partonic state, with two gluons coming from the target and one gluon from the projectile. This mechanism involves double gluon density and thus it enters at a non-leading twist, but it is enhanced at large energies due to large double gluon density at small x. The three-gluon contribution to J/psi hadroproduction is calculated within perturbative QCD in the k_T factorization framework, and it is found to provide a significant correction to the standard leading twist cross-section at the energies of the Tevatron or the LHC. The results are given as differential p_T-dependent cross-sections for J/psi polarization components.