Speaker
Description
We calculate the cos 2φ asymmetry in J/ψ production in electron-proton collision for the kinematics
of the planned electron-ion collider (EIC). This directly probes the Weisz¨acker-Williams (WW) type
linearly polarized gluon distribution. Assuming generalized factorization, we calculate the asymmetry
at next-to-leading-order (NLO) when the energy fraction of the J/ψ satisfies z < 1 and the dominating
subprocess is γ∗ + g → c + ¯c + g. We use non-relativistic QCD based color singlet (CS) model for J/ψ
production. We investigate the small x region which will be accessible at the EIC. We present the
upper bound of the asymmetry, as well as estimate it using a (i) Gaussian type parametrization for the
TMDs and (ii) McLerran-Venugopalan (MV) model at small x. We find small but sizable asymmetry
in all the three cases.
