Effective transverse momentum in multiple jet production at hadron colliders

TL;DR

The paper introduces a new variable, $k_T^{ m ness}$, that effectively captures jet resolution in collider processes, enabling improved higher-order QCD calculations and stable phenomenological predictions for jet production at the LHC.

Contribution

A novel jet resolution variable, $k_T^{ m ness}$, is proposed to better handle unresolved jets and facilitate advanced QCD computations in collider physics.

Findings

$k_T^{ m ness}$ accurately characterizes the $N+1$ to $N$-jet transition.

The variable demonstrates stability against hadronization and multiple-parton interactions.

Application to $H$+jet and $Z$+2 jet processes shows improved NLO correction evaluations.

Abstract

We consider the class of inclusive hadron collider processes in which several energetic jets are produced, possibly accompanied by colourless particles (such as Higgs boson(s), vector boson(s) with their leptonic decays, and so forth). We propose a new variable that smoothly captures the $N+1$ to $N$-jet transition. This variable, that we dub $k_T^{\rm ness}$, represents an effective transverse momentum controlling the singularities of the $N+1$-jet cross section when the additional jet is unresolved. The $k_T^{\rm ness}$ variable offers novel opportunities to perform higher-order calculations in Quantum Chromodynamics (QCD) by using non-local subtraction schemes. We study the singular behavior of the $N+1$-jet cross section as $k_T^{\rm ness}\to 0$ and, as a phenomenological application, we use the ensuing results to evaluate next-to-leading order corrections to $H$+jet and $Z$+2 jet production at the LHC. We show that $k_T^{\rm ness}$ performs extremely well as a resolution variable and appears to be very stable with respect to hadronization and multiple-parton interactions.