Small-$p_T$ and large-$x$ regions for Higgs transverse momentum distributions

TL;DR

This paper presents an improved resummation formalism combining small-$p_T$ and large-$x$ effects for Higgs boson production at the LHC, enhancing theoretical predictions across different transverse momentum regions.

Contribution

It introduces a combined threshold-improved $p_T$ and threshold resummation approach for Higgs production, achieving higher accuracy up to NNLL and NNLL* levels.

Findings

Faster convergence of perturbative series at small $p_T$.

Improved agreement with fixed-order calculations at medium and large $p_T$.

Abstract

It was shown recently that standard resummation of logarithms of $Q/p_T$ can be supplemented with the resummation of logarithmic contributions at large $x=Q^2/s$ in the case of a colourless final state such as Higgs produced via gluon fusion or the production of a lepton pair via Drell--Yan mechanism. Such an improved transverse momentum resummation takes into account soft emissions that are emitted at very small angles. We report on recent phenomenological studies of a combined threshold-improved $p_T$ and threshold resummation formalism to the Higgs boson produced at the LHC where small-$p_T$ and threshold logarithms are resummed up to NNLL and NNLL* respectively. We show that the effect of the modified $p_T$ resummation yields a faster perturbative convergence in the small-$p_T$ region while the effect of the threshold one improves the agreement with fixed-order calculations in the medium and large-$p_T$ regions.