A first determination of the unpolarized quark TMDs from a global analysis

TL;DR

This paper presents the first extraction of unpolarized quark transverse momentum dependent distributions (TMDs) from a combined analysis of various scattering processes, using leading-order QCD with advanced scale evolution techniques.

Contribution

It introduces a novel global analysis method to determine unpolarized quark TMDs from multiple experimental data sets at leading order in QCD.

Findings

First determination of unpolarized quark TMDs from combined data

Effective handling of low scale evolution around 1 GeV$^2$

No need for high transverse momentum matching

Abstract

Transverse momentum dependent distribution and fragmentation functions of unpolarized quarks inside unpolarized protons are extracted, for the first time, through a simultaneous analysis of semi-inclusive deep-inelastic scattering, Drell-Yan and $Z$ boson hadroproduction processes. This study is performed at leading order in perturbative QCD, with energy scale evolution at the next-to-leading logarithmic accuracy. Moreover, some specific choices are made to deal with low scale evolution around 1 GeV$^2$. Since only data in the low transverse momentum region are considered, no matching to fixed-order calculations at high transverse momentum is needed.