Exploring the SMEFT at dimension-8 with Drell-Yan transverse momentum measurements

TL;DR

This paper shows that measuring the transverse momentum distribution in Drell-Yan processes can reveal new dimension-8 effects in the SMEFT, especially with future high-luminosity LHC data.

Contribution

It introduces the use of invariant mass-binned transverse momentum measurements to probe unexplored dimension-8 SMEFT operators involving four-fermion and QCD field strength tensors.

Findings

Current LHC data can partially probe these operators.

Future HL-LHC data can significantly enhance sensitivity.

The method helps distinguish different ultraviolet completions of SMEFT.

Abstract

We demonstrate that measurements of the neutral-current Drell-Yan transverse momentum distribution binned in invariant mass are sensitive to unexplored dimension-8 parameters of the Standard Model Effective Field Theory (SMEFT). These distributions are sensitive to four-fermion operators with additional QCD field strength tensors. The determination of the Wilson coefficients of these operators provides a useful diagnostic tool that distinguishes possible ultraviolet completions of the SMEFT. We study how well these effects can be probed by current LHC data, and explore the sensitivity of the future high-luminosity LHC (HL-LHC) to these operators. We find that the HL-LHC data has the potential to strongly probe this sector of the SMEFT.