Cos2ϕt azimuthal asymmetry in back-to-back J/ψ -jet production in ep→eJ/ψ jet X at the EIC

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.