Drell-Yan $p_{\bot}$ spectra from fixed-target to LHC energies based on Parton Branching TMDs matched with NLO

TL;DR

This paper develops a Parton Branching TMD approach matched with NLO calculations to accurately describe Drell-Yan transverse momentum spectra across a wide range of energies, from fixed-target to LHC.

Contribution

It introduces a novel matching of TMD evolution with NLO matrix elements within the Parton Branching framework for Drell-Yan processes.

Findings

Good agreement with experimental data from various experiments.

Effective description across different energy scales and kinematic regions.

Addresses matching issues in moderate to low mass and $p_{ot}$ regions.

Abstract

The theoretical description of Drell-Yan (DY) transverse momentum spectra over wide kinematic regions in energy, mass and transverse momentum requires not only fixed-order perturbative QCD calculations but also soft-gluon QCD resummations to all orders of perturbation theory. The latter are traditionally accomplished either by Parton Showers (PS) with Monte Carlo event generators or by (different versions of) analytical procedures. In this work we focus on issues involved in the matching of the fixed-order calculation and resummation, especially in the moderate to low mass and $p_{\bot}$ region. In particular we address the DY region accessible at fixed target experiments. We present a Parton Branching (PB) formulation in which transverse momentum dependent (TMD) evolution is matched with MCatNLO calculations of NLO matrix elements. Using this formulation, we show a good theoretical description of DY data from experiments in very different kinematic ranges: NuSea, R209, Phenix, LHC $8\;\textrm{TeV}$ and $13\;\textrm{TeV}$.