Measurement of high-mass t ¯t l+l− production and lepton flavour universality-inspired effective field theory interpretations at √s = 13 TeV with the ATLAS detector

Abstract

Measurements of t -t+- production in theregion of high dilepton invariant mass with effective fieldtheory (EFT) interpretations are presented. They are performedusing final states with three isolated leptons (electronsor muons) and are based onSQUARE ROOT s = 13 TeV proton-protoncollision data with an integrated luminosity of 140 fb-1,recorded from 2015 to 2018 with the ATLAS detector atthe Large Hadron Collider. Measurements of the t -t+-signal strength and cross-section upper-limits are performedinclusively in lepton flavour and separately for electrons andmuons. The study also aims to probe anomalous four-fermioninteractions including to test for possible lepton flavor universalityviolation. No significant deviations from the StandardModel predictions are observed and the measurementsare interpreted through the EFT formalism to provide new constraints on the relevant operators.