Combining $Q_T$ and small-$x$ resummations

TL;DR

This paper develops a combined resummation framework for transverse momentum and small-$x$ logarithms in colorless final state production, enhancing theoretical predictions for processes like Higgs and Drell-Yan at high energies.

Contribution

It introduces a method to jointly resum $Q_T$ and small-$x$ logarithms, providing new ingredients for improved theoretical accuracy in high-energy processes.

Findings

Derived the necessary ingredients for joint resummation.

Demonstrated how to supplement traditional $Q_T$ resummation with small-$x$ resummation.

Enhanced the theoretical description of Higgs and Drell-Yan production at high energies.

Abstract

We analyze transverse momentum ($Q_T$) resummation of a colorless final state, e.g. Higgs production in gluon fusion or the production of a lepton pair via the Drell-Yan mechanism, in the limit where the invariant mass of the final state is much less then the center-of-mass energy, i.e. $Q^2\ll s$. We show how the traditional resummation of logarithms of $Q_T/Q$ can be supplemented with the resummation of the leading logarithmic contributions at small $x=Q^2/s$ and we compute the necessary ingredients to perform such joint resummation.