Lepton-Charge and Forward-Backward Asymmetries in Drell-Yan Processes for Precision Electroweak Measurements and New Physics Searches

TL;DR

This paper investigates how combining lepton-charge and forward-backward asymmetry measurements in Drell-Yan processes can reduce PDF uncertainties, enhancing precision in electroweak parameter determination and new physics searches at the LHC.

Contribution

It introduces a method using combined asymmetry measurements analyzed with xFitter to improve PDF uncertainty reduction in Drell-Yan processes.

Findings

Asymmetry measurements help constrain PDFs near the vector-boson peak.

Combining charged current and neutral current asymmetries reduces uncertainties.

Results are relevant for both Standard Model and Beyond the Standard Model physics.

Abstract

Precision determinations of Standard Model (SM) Electro-Weak (EW) parameters at the Large Hadron Collider (LHC) are dominated by uncertainties due to Parton Distribution Functions (PDFs). Reweighting and profiling techniques are routinely employed to treat this. We explore approaches based on combining measurements of charged current and neutral current Drell-Yan (DY) asymmetries to improve PDF uncertainties. We present the results of a numerical analysis performed with the open-source platform xFitter. PDF uncertainties are examined for lepton-charge and forward-backward asymmetries in regions of transverse and invariant masses near the vector-boson peak, based on LHC Run III and HL-LHC luminosity scenarios. We discuss the complementarity of the asymmetries in reducing PDF uncertainties in observables relevant to both SM and Beyond the SM (BSM) physics.