Azimuthal asymmetries in semi-inclusive J /ψ+jet production at an EIC

D'Alesio U.;Murgia F.;Pisano C.;Taels P.

2019-01-01

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Abstract

We consider transverse momentum dependent gluon distributions inside both unpolarized and transversely polarized protons and show how they can be probed by looking at azimuthal modulations in ep -> eJ/psi jet X. We find that the contribution due to quark induced subprocesses is always suppressed in the considered kinematic regions, accessible in principle at a future electron-ion collider. Our model-independent estimates of the maximal values of these asymmetries allowed by positivity bounds suggest the feasibility of their measurement. In addition, by adopting the McLerran-Venugopalan model for the unpolarized and linearly polarized gluon densities, we study the behavior of the cos 2 phi asymmetries in the small-x limit.