Precision phenomenology with fiducial cross sections in the triple-differential Drell-Yan process

TL;DR

This paper analyzes high-precision LHC measurements of the triple-differential Drell-Yan process, combining advanced theoretical predictions to improve understanding of electroweak parameters and parton distributions.

Contribution

It provides detailed phenomenological predictions for the triple-differential Drell-Yan process using state-of-the-art perturbative calculations, accounting for fiducial cuts and higher-order corrections.

Findings

Identification of forbidden regions at Born level due to fiducial cuts

Demonstration of sensitivity to extra particle emissions at higher orders

Predictions enabling precise extraction of the weak mixing angle

Abstract

The production of lepton pairs (Drell-Yan process) at the LHC is being measured to high precision, enabling the extraction of distributions that are triply differential in the di-lepton mass and rapidity as well as in the scattering angle described by the leptons. The measurements are performed for a fiducial phase space, defined by cuts on the individual lepton momenta and rapidities. Based on the ATLAS triple-differential Drell-Yan measurement at 8~TeV, we perform a detailed investigation of the phenomenology of this process based on state-of-the-art perturbative predictions in QCD and the electroweak theory. Our results demonstrate the highly non-trivial interplay between measurement variables and fiducial cuts, which leads to forbidden regions at Born level, and induces sensitivity on extra particle emissions from higher perturbative orders. We also investigate the sensitivity of the measurement on parton distributions and electroweak parameters. We derive Standard-Model theory predictions which combine NNLO QCD and NLO EW corrections and include partial N$^3$LO QCD as well as higher-order EW corrections where appropriate. Our results will enable the use of the triple-differential Drell-Yan data in a precise experimental determination of the weak mixing angle.