Collinear and TMD distributions with dynamical soft-gluon resolution scale

TL;DR

This paper introduces a novel approach to parton distribution functions in QCD by incorporating a dynamical soft-gluon resolution scale, impacting both collinear and TMD distributions, with applications to LHC Drell-Yan data.

Contribution

It presents the first determination of parton distributions with a dynamical resolution scale at NLO, integrating this into fits to HERA data and applying to LHC Drell-Yan spectra.

Findings

Successful determination of dynamical resolution scale distributions at NLO

Application to Drell-Yan transverse momentum spectra at the LHC

Insights into non-perturbative intrinsic-kT parameters from data

Abstract

Soft-gluon resolution scales characterize parton branching Monte Carlo implementations of the evolution equations for parton distribution functions in Quantum Chromodynamics (QCD). We examine scenarios with dynamical, i.e., branching-scale dependent, resolution scale, and discuss physical implications for both collinear and transverse-momentum dependent (TMD) distributions. We perform the first determination of parton distributions with dynamical resolution scale, at next-to-leading order (NLO) in perturbation theory, from fits to precision deep-inelastic scattering measurements from HERA. We present an application of TMD distributions with dynamical resolution scale to Drell-Yan lepton-pair transverse momentum spectra at the LHC, and comment on the extraction of non-perturbative intrinsic-kT parameters from Drell-Yan data at small transverse momenta.