Underlying event sensitive observables in Drell-Yan production using GENEVA

TL;DR

This paper extends the GENEVA Monte Carlo framework to include multiple parton interactions, enabling precise predictions for underlying-event sensitive observables in Drell-Yan production and comparison with experimental data.

Contribution

It introduces a novel interface of GENEVA with PYTHIA8's MPI model, combining NNLO calculations with parton shower and MPI effects for detailed underlying-event studies.

Findings

Good agreement with ATLAS and CMS data on underlying-event observables

Demonstrates the ability to disentangle different physical effects in Drell-Yan production

Provides a framework for future precision studies of soft hadronic physics

Abstract

We present an extension of the GENEVA Monte Carlo framework to include multiple parton interactions (MPI) provided by PYTHIA8. This allows us to obtain predictions for underlying-event sensitive measurements in Drell-Yan production, in conjunction with GENEVA's fully-differential NNLO calculation, NNLL' resummation for the 0-jet resolution variable (beam thrust), and NLL resummation for the 1-jet resolution variable. We describe the interface with the parton shower algorithm and MPI model of PYTHIA8, which preserves both the precision of partonic N-jet cross sections in GENEVA as well as the shower accuracy and good description of soft hadronic physics of PYTHIA8. We present results for several underlying-event sensitive observables and compare to data from ATLAS and CMS as well as to standalone PYTHIA8 predictions. This includes a comparison with the recent ATLAS measurement of the beam thrust spectrum, which provides a potential avenue to fully disentangle the physical effects from the primary hard interaction, primary soft radiation, multiple parton interactions, and nonperturbative hadronization.