Polarized TMD fragmentation functions for $J/\psi$ production

TL;DR

This paper computes the leading-order matching of TMD fragmentation functions for light quarks and gluons to polarized $J/ar{psi}$ production using NRQCD, providing predictions relevant for future Electron-Ion Collider experiments.

Contribution

It introduces the first leading-order calculation of polarized TMD fragmentation functions for $J/ar{psi}$ within the NRQCD framework, linking perturbative and nonperturbative aspects.

Findings

Provides predictions for polarized $J/ar{psi}$ production in SIDIS.

Establishes a connection between TMDFFs and NRQCD matrix elements.

Enhances understanding of quark/gluon fragmentation into polarized quarkonia.

Abstract

We calculate the matching, at leading order, of the transverse momentum-dependent fragmentation functions (TMDFFs) for light quarks and gluons fragmenting to a $J/\psi$ onto polarized nonrelativistic QCD (NRQCD) TMDFFs. The NRQCD TMDFFs have an operator-product-expansion in terms of nonperturbative NRQCD production matrix elements. Using the results we obtain, we make predictions for the light quark fragmentation contribution to the production of polarized $J/\psi$ in semi-inclusive deep inelastic scattering (SIDIS) both for unpolarized and longitudinally polarized beams. These results are an important contribution to polarized $J/\psi$ production in SIDIS, and thus are needed for comparison with experiments at the future Electron-Ion Collider.