Top B Physics at the LHC

TL;DR

This paper proposes a novel method to measure CP violation in heavy flavor mixing using lepton charge correlations in top-pair events at the LHC, enabling new precision tests of the Standard Model and beyond.

Contribution

It introduces a new strategy for probing CP violation through lepton charge correlations in top decays, independent of previous methods.

Findings

Constructed two CP asymmetries based on lepton charge signs.

Estimated sensitivities of these asymmetries with current LHC data.

Demonstrated potential for precision CP violation measurements in b and c quark physics.

Abstract

In top-pair events where at least one of the tops decays semi-leptonically, the identification of the lepton charge allows to tag not only the top charge but also that of the subsequent b quark. In cases where the b also decays semi-leptonically, the charge of the two leptons can be used to probe CP violation in heavy flavor mixing and decays. This strategy to measure CP violation is independent of those adopted so far in experiments, and can already constrain non Standard Model sources of CP violation with current and near future LHC data. To demonstrate the potential of this method we construct two CP asymmetries based on same-sign and opposite-sign leptons and estimate their sensitivities. This proposal opens a new window for doing precision measurements of CP violation in b and c quark physics via high p_T processes at ATLAS and CMS.