Top polarization as a probe of new physics

TL;DR

This paper explores how top quark polarization measurements at the LHC can serve as a clean probe for detecting new high-mass vector resonances beyond the Standard Model, by analyzing decay lepton distributions.

Contribution

It introduces a method using lepton angular distributions from top decay to isolate effects of new physics in top production, unaffected by anomalous tbW couplings.

Findings

Sensitivity to new top couplings demonstrated

Lepton angular distributions effectively probe top polarization

Potential to identify new vector resonances at the LHC

Abstract

We investigate the effects of new physics scenarios containing a high mass vector resonance on top pair production at the LHC, using the polarization of the produced top. In particular we use kinematic distributions of the secondary lepton coming from top decay, which depends on top polarization, as it has been shown that the angular distribution of the decay lepton is insensitive to the anomalous tbW vertex and hence is a pure probe of new physics in top quark production. Spin sensitive variables involving the decay lepton are used to probe top polarization. Some sensitivity is found for the new couplings of the top.