Multi-jet Merging with TMD Parton Branching

TL;DR

This paper introduces a novel method that integrates transverse momentum dependent (TMD) distributions into multi-jet merging algorithms, improving the modeling of jet multiplicities and kinematic distributions at high-energy colliders.

Contribution

The paper presents a new approach to include initial-state transverse momentum recoils in multi-jet merging using TMD parton branching, enhancing accuracy in collider simulations.

Findings

Reduced dependence on merging scale.

Improved modeling of jet transverse momentum spectra.

Better agreement with experimental data on jet multiplicities.

Abstract

One of the main theoretical systematics in studies of final states with large jet multiplicities at high-energy hadron colliders is associated with the merging of QCD parton showers and hard-scattering matrix elements. We present a method to incorporate the physics of transverse momentum recoils due to initial-state shower evolution into multi-jet merging algorithms by using the concept of transverse momentum dependent (TMD) distributions and the associated parton branching. We investigate the dependence on the merging scale and illustrate the impact of the new method at the level of both exclusive and inclusive final-state observables by studying differential jet rates, transverse momentum spectra and multiplicity distributions, using vector boson + jets events at the LHC as a case study.