NLO JIMWLK evolution with massive quarks

TL;DR

This paper extends the NLO JIMWLK evolution equations to include effects of finite quark masses, addressing new IR divergences and enhancing the precision of gluon saturation models.

Contribution

It computes the evolution kernels with finite quark masses, introducing a mass-dependent counter term to cancel new IR divergences, advancing theoretical tools for gluon saturation.

Findings

Derived the light-cone wave function up to ${ m O}(g^3)$ with massive quarks.

Identified and canceled a new IR divergence caused by quark mass effects.

Extended the applicability of NLO JIMWLK evolution in phenomenological models.

Abstract

NLO evolution of the Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner (JIMWLK) equation with massless quarks was derived a few years ago. We make a step further to compute the evolution kernels focusing on the effects due to finite quark masses. To this goal, the light-cone wave function of a fast moving dilute hadronic projectile is computed up to ${\cal O}(g^3)$ in QCD coupling constant. Compared with the massless case, a new IR divergence emerges, which is eventually canceled by a mass dependent counter term. Our results extend the theoretical tools used in physics of gluon saturation and aim at improving precision in future phenomenological applications.