On the transverse momentum in Z-boson production in a virtuality ordered parton shower

TL;DR

This paper investigates whether a virtuality ordered parton shower accurately reproduces the transverse momentum distribution of Z-bosons in hadron collisions, finding it effectively sums large logarithms as expected.

Contribution

The study demonstrates that a virtuality ordered parton shower effectively captures the known QCD results for Z-boson transverse momentum distributions.

Findings

Virtuality ordered shower reproduces known QCD results

Effective in summing large logarithms in perturbative calculations

Validates the use of virtuality ordering in parton showers

Abstract

Cross sections for physical processes that involve very different momentum scales in the same process will involve large logarithms of the ratio of the momentum scales when calculated in perturbation theory. One goal of calculations using parton showers is to sum these large logarithms. We ask whether this goal is achieved for the transverse momentum distribution of a Z-boson produced in hadron-hadron collisions when the shower is organized with higher virtuality parton splittings coming first, followed successively by lower virtuality parton splittings. We find that the virtuality ordered shower works well in reproducing the known QCD result.