Transverse momentum dependent parton densities in processes with heavy quark generations

TL;DR

This paper employs a TMD gluon distribution derived from the Kimber-Martin-Ryskin approach to accurately describe heavy quark production data from HERA, comparing it with other QCD models across various kinematic ranges.

Contribution

It introduces a TMD gluon distribution based on Bessel-inspired behavior and demonstrates its effectiveness in describing heavy quark production data, comparing it with other evolution equations and perturbative calculations.

Findings

Good agreement with HERA data for charm and bottom production

TMD approach outperforms some conventional pQCD calculations

Comparison with CCFM evolution shows consistent results

Abstract

To study the heavy quark production processes, we use the transverse momentum dependent (TMD, or unintegrated) gluon distribution function in a proton obtained recently using the Kimber-Martin-Ryskin prescription from the Bessel-inspired behavior of parton densities at small Bjorken $x$ values. We obtained a good agreement of our results with the latest HERA experimental data for reduced cross sections $\sigma^{c\overline{c}}_{\rm red}(x,Q^2)$ and $\sigma^{b\overline{b}}_{\rm red}(x,Q^2)$, and also for deep inelastic structure functions $F_2^c(x,Q^2)$ and $F_2^b(x,Q^2)$ in a wide range of $x$ and $Q^2$ values. Comparisons with the predictions based on the Ciafaloni-Catani-Fiorani-Marchesini evolution equation and with the results of conventional pQCD calculations performed at first three orders of perturbative expansion are presented.