Status and prospects for $CPT$ and Lorentz invariance violation searches in neutral meson mixing

TL;DR

This paper reviews current experimental bounds on CPT violation in neutral meson mixing, presents new measurements, and discusses how LHCb can improve constraints on Lorentz invariance violation within the Standard-Model Extension framework.

Contribution

It provides updated bounds on CPT asymmetry in meson systems and forecasts how LHCb can significantly enhance sensitivity to Lorentz-violating effects.

Findings

New bounds on CPT asymmetry in B0 and Bs0 systems.

LHCb's potential to improve SME coefficient constraints by up to two orders of magnitude.

Identification of sidereal- and boost-dependent variations in CPT violation effects.

Abstract

An overview of current experimental bounds on $CPT$ violation in neutral meson mixing is given. New values for the $CPT$ asymmetry in the $B^0$ and $B_s^0$ systems are deduced from published BaBar, Belle and LHCb results. With dedicated analyses, LHCb will be able to further improve the bounds on $CPT$ violation in the $D^0$, $B^0$ and $B_s^0$ systems. Since $CPT$ violation implies violation of Lorentz invariance in an interacting local quantum field theory, the observed $CPT$ asymmetry will exhibit sidereal- and boost-dependent variations. Such $CPT$-violating and Lorentz-violating effects are accommodated in the framework of the Standard-Model Extension (SME). The large boost of the neutral mesons produced at LHCb results in a high sensitivity to the corresponding SME coefficients. For the $B^0$ and $B_s^0$ systems, using existing LHCb results, we determine with high precision the SME coefficients that are not varying with sidereal time. With a full sidereal analysis, LHCb will be able to improve the existing SME bounds in the $D^0$, $B^0$ and $B_s^0$ systems by up to two orders of magnitude.