Drell-Yan Production at NNLL'+NNLO Matched to Parton Showers

TL;DR

This paper introduces a novel Monte Carlo framework combining NNLO calculations with NNLL' resummation for Drell-Yan production, improving theoretical accuracy and agreement with LHC data.

Contribution

It develops a matched NNLO and NNLL' resummation framework integrated with parton showers, enhancing precision for Drell-Yan predictions.

Findings

Improved agreement with LHC measurements for resummation-sensitive observables.

Enhanced perturbative accuracy beyond traditional parton shower approximations.

Systematic assessment of theoretical uncertainties in Drell-Yan predictions.

Abstract

We present results for Drell-Yan production from the GENEVA Monte-Carlo framework. We combine the fully-differential NNLO calculation with higher-order resummation in the 0-jettiness resolution variable. The resulting parton-level events are further combined with parton showering and hadronization provided by PYTHIA8. The 0-jettiness resummation is carried out to NNLL', which consistently incorporates all singular virtual and real NNLO corrections. It thus provides a natural perturbative connection between the NNLO calculation and the parton shower regime, including a systematic assessment of perturbative uncertainties. In this way, inclusive observables are correct to NNLO, up to small power corrections in the resolution cutoff. Furthermore, the perturbative accuracy of 0-jet-like resummation variables is significantly improved beyond the parton shower approximation. We provide comparisons with LHC measurements of Drell-Yan production at 7 TeV from ATLAS, CMS, and LHCb. As already observed in $e^+e^-$ collisions, for resummation-sensitive observables, the agreement with data is noticeably improved by using a lower value of $\alpha_s(M_Z) = 0.1135$.