Lorentz and CPT Violation in Top-Quark Production and Decay

TL;DR

This paper explores how to test Lorentz and CPT symmetry violations in top-quark production and decay processes at colliders, providing theoretical tools and matrix elements for experimental searches.

Contribution

It introduces the relevant Lagrangian, derives matrix elements for top-quark processes with Lorentz violation, and highlights single-top production as a promising CPT violation test.

Findings

Matrix elements for top-antitop production with Lorentz violation

Matrix elements for single-top production channels

Applicability to collider experiments like the LHC

Abstract

The prospects are explored for testing Lorentz and CPT symmetry in the top-quark sector. We present the relevant Lagrange density, discuss physical observables, and describe the signals to be sought in experiments. For top-antitop pair production via quark or gluon fusion with subsequent semileptonic or hadronic decays, we obtain the matrix element in the presence of Lorentz violation using the narrow-width approximation. The issue of testing CPT symmetry in the top-quark sector is also addressed. We demonstrate that single-top production and decay is well suited to a search for CPT violation, and we present the matrix elements for single-top production in each of the four tree-level channels. Our results are applicable to searches for Lorentz violation and studies of CPT symmetry in collider experiments, including notably high-statistics top-antitop and single-top production at the Large Hadron Collider.