$B_s\to D_s K$ as a Probe of CPT Violation

TL;DR

This paper explores how to detect CPT violation in the $B_s$ meson system at the LHC by constructing observables from decay rates that can distinguish CPT-violating new physics from CPT-conserving models, focusing on the $B_s o D_s K$ decay mode.

Contribution

It introduces a method to identify CPT violation in $B_s$ mixing using specific decay observables, applicable even if CPT violation occurs in both mixing and decay.

Findings

Proposes a measurable observable for CPT violation in $B_s$ decays.

Shows how to differentiate CPT-violating models from CPT-conserving ones.

Discusses the applicability of the method under various CPT violation scenarios.

Abstract

We discuss some possible signals of CPT violation in the $B_s$ system that may be probed at the Large Hadron Collider (LHC). We show how one can construct combinations ofobservables coming from tagged and untagged decay rates of $B_s\to D_s^\pm K^\mp$ that can unambiguously differentiate between CPT violating and CPT conserving new physics (NP) models contributing in $B_s-\bar B_s$ mixing. We choose this particular mode as an illustrative example for two reasons: (i) In the Standard Model, there is only one decay amplitude, so it is easier to untangle any new physics; (ii) $B_s$ being a neutral meson, it is possible to unambiguously identify any sign of CPT violation that occurs only in mixing but not in decay. We define an observable which is useful to extract the CPT violating parameter in $B_s$ decay, and also discuss how far the results are applicable even if CPT violation is present in both mixing and decay.