TMD evolution effect on $\cos2\phi$ azimuthal asymmetry in a back-to-back production of $J/\psi$ and jet at the EIC

TL;DR

This paper investigates how TMD evolution influences the $ ext{cos}2 ext{phi}$ azimuthal asymmetry in back-to-back $J/ ext{psi}$ and jet production at the EIC, highlighting the dependence on non-perturbative and perturbative parameterizations.

Contribution

It extends previous work by analyzing TMD evolution effects on azimuthal asymmetry using different parameterizations and NRQCD estimates for $J/ ext{psi}$ production.

Findings

TMD evolution causes a small but increasing asymmetry with transverse momentum imbalance.

The asymmetry's magnitude depends on non-perturbative Sudakov factors and perturbative evolution kernels.

Different LDME sets affect the estimated $J/ ext{psi}$ production and asymmetry.

Abstract

A back-to-back semi-inclusive $J/\psi + jet$ production is a promising process to study gluon transverse momentum distribution (TMDs) at the future electron-ion collider (EIC). A back-to-back configuration allows a higher transverse momentum for $J/\psi$. We present an extension of a previous work where we studied $\cos2\phi$ azimuthal asymmetry within the TMD factorization framework for this process. We present and compare the effect of TMD evolution on the asymmetry, in two approaches that differ in the parameterization of the perturbative tails of the TMDs and the non-perturbative factors. We show that the asymmetry depends on the parameterizations of the non-perturbative Sudakov factors in the larger $b_T$ region and on the perturbative part of the evolution kernel. We use NRQCD to estimate the $J/\psi$ production and show the effect of using different long-distance matrix element (LDME) sets. Overall, the asymmetry after incorporating TMD evolution is small, but increases with the transverse momentum imbalance of the $J/\psi$-jet pair.