Production of $S$-wave charmonia in the soft gluon resummation approach using the NRQCD

TL;DR

This paper models $S$-wave charmonium production at small transverse momenta using soft gluon resummation within the NRQCD framework, combining TMD and collinear approaches for comprehensive predictions at collider energies.

Contribution

It introduces an inverse-error weighting scheme to merge TMD and collinear predictions, extending the applicability to intermediate transverse momenta in charmonium production.

Findings

Predicted cross sections for $ ext{η}_c$ and $J/ψ$ at various collider energies.

Provided transverse momentum spectra for charmonium states.

Presented polarized $J/ψ$ production predictions.

Abstract

In this article, we study the $S-$wave charmonium production at the small transverse momenta in the transverse momentum dependent (TMD) parton model (PM), as it is formulated in the soft gluon resummation (SGR) approach , using the nonrelativistic quantum chromodynamics (NRQCD) as the model of the heavy quarkonium hadronization. To extend the scope of the calculation to the phenomenologically important region of intermediate transverse momenta, we use the inverse-error weighting (InEW) matching scheme to combine the TMD PM predictions with the results of the collinear PM (CPM) fixed-order calculations, which are applicable at the large transverse momenta. We predict the direct $\eta_c$ and the prompt $J/\psi$ production cross sections and transverse momentum spectra in proton-proton collisions at the LHC, RHIC, AFTER and NICA energies. Predictions for the polarized $J/\psi$ production processes are also presented.