Kinematic distributions of the $\eta_c$ leptoproduction in association with light hadrons

TL;DR

This paper calculates the $ ext{η}_c$ meson leptoproduction using nonrelativistic QCD, revealing the dominant role of the colour-singlet channel and providing detailed differential cross sections for future experimental comparisons.

Contribution

First calculation of $ ext{η}_c$ leptoproduction within nonrelativistic QCD, highlighting the significance of the colour-singlet channel contrary to previous expectations.

Findings

Colour-singlet channel dominates production.

Differential cross sections provided for HERA and EIC.

Scale and matrix-element dependencies analyzed.

Abstract

The $\eta_c$ meson leptoproduction is calculated within the nonrelativistic QCD framework for the first time. It is found that the colour-singlet channel, although suppressed by a factor of $\alpha_s$ relative to the colour-octet ones, provides the most important contribution for almost all the experimental conditions, which disagrees with some of the expectations before computation. We present the differential cross sections with respect to $p_t^2$, $p_t^{\star2}$, $Q^2$, $W$, and $z$, for both HERA and EIC experimental conditions as a reference for future studies. The scale dependence and long-distance-matrix-element dependence are also investigated in this paper.