Probing the low transverse momentum domain of Z production with novel variables

TL;DR

This paper presents a detailed phenomenological analysis of the novel  variable in low transverse momentum Z boson production, demonstrating excellent agreement with experimental data and highlighting its potential to probe non-perturbative QCD effects.

Contribution

It provides the first comprehensive theoretical study of the  variable with advanced resummation and matching techniques, enhancing understanding of low transverse momentum QCD dynamics.

Findings

Excellent agreement between theory and data over the entire  range

Demonstrates the  variable's sensitivity to non-perturbative effects

Shows potential for future constraints on non-perturbative QCD models

Abstract

The measurement of the low transverse momentum region of vector boson production in Drell-Yan processes has long been invaluable to testing our knowledge of QCD dynamics both beyond fixed-order in perturbation theory as well as in the non-perturbative region. Recently the D\O\ collaboration have introduced novel variables which lead to improved measurements compared to the case of the standard QT variable. To complement this improvement on the experimental side, we develop here a complete phenomenological study dedicated in particular to the new \phi* variable. We compare our study, which contains the state-of-the-art next-to-next-to-leading resummation of large logarithms and a smooth matching to the full next-to-leading order result, to the experimental data and find excellent agreement over essentially the entire range of \phi*, even without direct inclusion of non-perturbative effects. We comment on our findings and on the potential for future studies to constrain non-perturbative behaviour.