CPT and Lorentz violation as signatures for Planck-scale physics

TL;DR

This paper reviews how potential CPT and Lorentz symmetry violations at the Planck scale could serve as signatures of quantum gravity, discussing theoretical mechanisms, the SME framework, and experimental tests involving matter-antimatter comparisons.

Contribution

It provides a comprehensive overview of mechanisms for spacetime-symmetry breaking and the experimental tests for CPT and Lorentz violation within the SME framework.

Findings

Discussion of theoretical models for symmetry breaking

Review of the Standard-Model Extension test framework

Analysis of experimental CPT tests with matter-antimatter comparisons

Abstract

In recent years, the breakdown of spacetime symmetries has been identified as a promising research field in the context of Planck-scale phenomenology. For example, various theoretical approaches to the quantum-gravity problem are known to accommodate minute violations of CPT invariance. This talk covers various topics within this research area. In particular, some mechanisms for spacetime-symmetry breaking as well as the Standard-Model Extension (SME) test framework will be reviewed; the connection between CPT and Lorentz invariance in quantum field theory will be exposed; and various experimental CPT tests with emphasis on matter--antimatter comparisons will be discussed.