Polarized J/ψ production in semi-inclusive DIS at large Q^2: Comparing quark fragmentation and photon-gluon fusion

We compare the relative importance of different mechanisms for polarized J/ψ production in semi-inclusive deep inelastic scattering processes at large Q^2. The transverse momentum dependent (TMD) factorization framework and nonrelativistic quantum chromodynamics are used to study the leading contributions from light quark fragmentation to polarized J/ψ, and compared to direct production via photon-gluon fusion, which can proceed through color-singlet as well as color-octet mechanisms. We identify kinematic regimes where light quark fragmentation dominates, allowing for the extraction of the ^3S_1^[8] matrix element, as well as regimes where photon gluon fusion dominates, suggesting that the gluon TMD parton distribution function can be probed.