A Case Study of the Sensitivity to LFV Operators with Precision Measurements and the LHC

TL;DR

This study compares how precision lepton flavor measurements and LHC data constrain lepton-flavor violating operators, highlighting the complementary roles of each method depending on quark mass and providing bounds on new physics scales.

Contribution

It provides a detailed comparison of the sensitivity of precision measurements and LHC searches to dimension-six LFV operators, emphasizing their complementarity.

Findings

Precision measurements set stronger constraints for light quarks.

LHC data complements precision measurements for operators with heavy quarks.

Bounds on the cutoff scale Λ > 600-800 GeV for certain operators using LHC run 1 data.

Abstract

We compare the sensitivity of precision measurements of lepton flavour observables to the reach of the LHC in a case study of lepton-flavour violating operators of dimension six with two leptons and two quarks. For light quarks precision measurements always yield the more stringent constraints. The LHC complements precision measurements for operators with heavier quarks. Competitive limits can already be set on the cutoff scale $\Lambda$ > 600 - 800 GeV for operators with right-handed $\tau$ leptons using the LHC run 1 data.