Charm Hadroproduction in $k_T$-Factorization Approach

TL;DR

This paper compares the LO collinear parton model and the $k_T$-factorization approach for heavy quark production, demonstrating that the latter effectively includes higher-order contributions in high-energy hadron collisions.

Contribution

It provides a detailed comparison of the two approaches and shows how $k_T$-factorization at LO captures effects typically associated with NLO and NNLO calculations.

Findings

$k_T$-factorization accounts for many higher-order contributions.

Differences are analyzed using simple gluon structure functions.

The approach effectively includes NLO and NNLO effects.

Abstract

We compare the theoretical status and the numerical predictions of two approaches for heavy quark production in the high energy hadron collisions, namely the conventional LO parton model with collinear approximation and $k_T$-factorization approach. The main assumptions used in the calculations are discussed. To extract the differences coming from the matrix elements we use very simple gluon structure function and fixed coupling. It is shown that the $k_T$-factorization approach calculated formally in LO and with Sudakov form factor accounts for many contributions related usually to NLO (and even NNLO) processes of the conventional parton model