Probing top anomalous couplings at the LHC with trilepton signatures in the single top mode

TL;DR

This paper explores the potential of trilepton signatures at the LHC to detect anomalous top quark couplings, providing a new method to constrain flavor-changing neutral interactions involving top quarks, Z-bosons, and gluons.

Contribution

It introduces a novel approach to simultaneously probe top anomalous couplings to Z-bosons and gluons using trilepton final states at the LHC.

Findings

Effective coupling strengths of 0.1-1 TeV^-1 can be probed.

Branching fractions of top quarks into lighter quarks and gluons or Z-bosons can be constrained below 0.1-1%.

The method enhances sensitivity to flavor-changing neutral interactions.

Abstract

We investigate trilepton final states to probe top anomalous couplings at the Large Hadron Collider. We focus on events originating from the associated production of a single top quark with a Z-boson, a channel sensitive to several flavor-changing neutral interactions of top and up/charm quarks. In particular, we explore a way to access simultaneously their anomalous couplings to Z-bosons and gluons and derive the discovery potential of trilepton final states to such interactions with 20 fb-1 of 8 TeV collisions. We show that effective coupling strengths of O(0.1-1) TeV-1 can be reached. Equivalently, branching fractions of top quarks into lighter quarks and gluons or Z-bosons can be constrained to be below O(0.1-1)%.