Calculation of the Z+jet cross section including transverse momenta of initial partons

TL;DR

This paper calculates the Z+jet cross section at the LHC considering initial parton transverse momenta, using TMD parton densities and parton showers, and compares predictions with experimental data.

Contribution

It introduces a method combining TMD parton densities with parton showers for Z+jet cross section calculations, aligning kT-factorization with NLO results.

Findings

Good agreement between kT-factorization and NLO calculations.

Forward region predictions from kT-factorization and hybrid factorization agree.

Predictions match LHCb measurements at 7 TeV.

Abstract

We perform calculations of Z+jet cross-section taking into account the transverse momenta of the initial partons. Transverse Momentum Dependent (TMD) parton densities obtained with the Parton Branching method are used and higher order corrections are included via TMD parton showers in the initial state. The predictions are compared to measurements of forward Z+jet production of the LHCb collaboration at $\sqrt{s}=7$ TeV. We show that the results obtained in kT-factorization are in good agreement with results obtained from a NLO calculation matched with traditional parton showers. We also demonstrate that in the forward rapidity region, kT-factorization and hybrid factorization predictions agree with each other.