Probing non-standard top-quark couplings via optimal-observable analyses at LHC

TL;DR

This paper investigates non-standard top-quark couplings at the LHC using optimal-observable analysis of charged-lepton distributions in top-quark pair production and decay, aiming to estimate measurement uncertainties of these couplings.

Contribution

It introduces an optimal-observable method to analyze non-standard top-quark couplings via effective Lagrangian in LHC processes, providing a new approach to quantify measurement uncertainties.

Findings

Estimates statistical uncertainties for non-standard couplings.

Analyzes charged-lepton distributions in top-quark events.

Provides a framework for probing new physics in top-quark interactions.

Abstract

Focusing attention on top-quark pair production and its decay processes at the LHC, non-standard top-quark couplings are studied based on the effective Lagrangian constructed with SU(3)X SU(2)X U(1) invariant dimension-6 operators. The optimal-observable analysis is carried out for the charged-lepton distributions in pp -> t t-bar X -> l^+ X' (l=e or mu) in order to estimate the expected statistical uncertainties in measurements of those non-standard t t-bar g and tbW couplings that contribute to this process in the leading order.