Discovery potential for $T' \to tZ$ in the trilepton channel at the LHC

TL;DR

This study evaluates the LHC's ability to discover heavy top partners decaying into a top quark and a Z boson via a clean trilepton final state, demonstrating effective analysis methods and sensitivity across mass ranges.

Contribution

It presents a comprehensive analysis of the discovery potential for $T'$ in the trilepton channel, comparing simple cut-and-count and multivariate methods, and explores reinterpretation in terms of anomalous couplings.

Findings

Simple cut-and-count analysis is as effective as multivariate methods.

Trilepton channel is highly sensitive, especially at higher $T'$ masses.

Reinterpretation in terms of top-$Z$-up anomalous coupling is feasible.

Abstract

The LHC discovery potential of heavy top partners decaying into a top quark and a $Z$ boson is studied in the trilepton channel at $\sqrt{s}=13$ TeV. The clean multilepton final state allows to strongly reduce the background contaminations and to reconstruct the $T'$ mass. We show that a simple cut-and-count analysis probes the parameter space of a simplified model as efficiently as a dedicated multivariate analysis. The trilepton signature finally turns out to be as sensitive in the low $T'$ mass region as the complementary channel with a fully hadronic top quark, and more sensitive in the large mass domain. The reinterpretation in terms of the top-$Z$-up anomalous coupling is shown.