Differential heavy quark pair production at small $x$

TL;DR

This paper extends small-$x$ resummation techniques to differential distributions in heavy quark pair production at high energies, improving the accuracy of theoretical predictions for collider experiments like the LHC.

Contribution

It introduces a method to resum high-energy logarithms for differential distributions in heavy quark pair production, implemented in the HELL code.

Findings

Enhanced theoretical predictions for heavy quark pair production at small $x$

Resummation improves perturbative stability of differential distributions

Applicable to LHC energies and future collider analyses

Abstract

We consider the production of a heavy quark pair in proton-proton collisions. For bottom and charm quarks, the final state invariant mass is typically much smaller than the collider energy (e.g. at the LHC), so that high-energy logarithms may spoil the perturbativity of the theoretical prediction at fixed order. The resummation of these logarithms to all orders is thus needed to obtain reliable predictions. In this work, we extend previous results on high-energy (or small-$x$) resummation to differential distributions in rapidity, transverse momentum and invariant mass, and implement them in the public code HELL.