Prospects for Lorentz invariance violation searches with top pair production at the LHC and future hadron colliders

Aurélien Carle,Stéphane Perriès,Nicolas Chanon

doi:10.1140/epjc/s10052-020-7715-2

Abstract

This paper investigates the impact of hypothetical Lorentz invariance violation on the tbar{t} production at the LHC and future hadron colliders. Possible deviations from Lorentz symmetry remain poorly constrained in the top quark sector. With a dedicated analysis of tbar{t} events produced at the LHC, bounds in the top sector can be improved by up to three orders of magnitude relative to the only measurement existing so far, performed at Tevatron. The sensitivity will be even further enhanced at the HL-LHC and future colliders.

Highlights

IntroductionLorentz Invariance is a fundamental symmetry of the Standard Model (SM), it is not expected to be conserved necessarily at the high energy scale of quantum gravity (e.g. in string theory [1] or quantum loop gravity [2]) where spacetime could undergo violent fluctuations
Lorentz Invariance is a fundamental symmetry of the Standard Model (SM), it is not expected to be conserved necessarily at the high energy scale of quantum gravity where spacetime could undergo violent fluctuations
This paper investigates the impact of hypothetical Lorentz invariance violation on the ttproduction at the LHC and future hadron colliders

Summary

Introduction

Lorentz Invariance is a fundamental symmetry of the Standard Model (SM), it is not expected to be conserved necessarily at the high energy scale of quantum gravity (e.g. in string theory [1] or quantum loop gravity [2]) where spacetime could undergo violent fluctuations. The most recent search for LIV and CPT breaking in the b-quark sector was performed at LHCb, using changes in B(s) mixing with sidereal time [10]. No evidence for LIV was found, with a 10% absolute uncertainty on the measured Lorentz violating (and CPT-conserving) SME coefficients [11]. This sensitivity, well below the precision obtained in the other quark sectors, calls for new measurements at present and future colliders. The LHC is a top factory, producing top quark pairs (tt) at a high rate, and provides a unique opportunity for measuring precisely SME coefficients in the top sector. We will derive the expected sensitivity to LIV using the top pair production signature

Theoretical setup

Top pair production in the SME

Anatomy of the LIV signatures in t t

Sensitivity at the LHC and future colliders

Conclusions