$\cos2\phi_t$ azimuthal asymmetry in back-to-back $J/\psi$-jet production in $e~p\rightarrow e~J/\psi~Jet~ X$ at the EIC

TL;DR

This paper studies the $ ext{cos}2 ext{phi}_t$ azimuthal asymmetry in back-to-back $J/ ext{psi}$-jet production at the EIC, using the GPM framework with NRQCD to include color singlet and octet contributions, and explores TMD effects.

Contribution

It provides a detailed analysis of the azimuthal asymmetry in $J/\psi$-jet production incorporating NRQCD and TMD evolution, offering predictions for future EIC measurements.

Findings

Quantifies the $ ext{cos}2 ext{phi}_t$ asymmetry with different gluon TMD parameterizations.

Shows the impact of TMD evolution on the asymmetry.

Breaks down contributions from various NRQCD states.

Abstract

In this article, we investigate the $\cos2\phi_t$ azimuthal asymmetry in $e ~p\rightarrow e ~J/\psi ~Jet~ X$, where the $J/\psi$-jet pair is almost back-to-back in the transverse plane, within the framework of the generalized parton model(GPM). We use non-relativistic QCD(NRQCD) to calculate the $J/\psi$ production amplitude and incorporate both color singlet(CS) and color octet(CO) contributions to the asymmetry. We estimate the asymmetry using different parameterizations of the gluon TMDs in the kinematics that can be accessed at the future electron-ion collider (EIC) and also investigate the impact of transverse momentum dependent (TMD) evolution on the asymmetry. We present the contributions coming from different states to the asymmetry in NRQCD.