Search for CP and CPT violation in positronium decay

TL;DR

This paper investigates potential CP and CPT violations in positronium decay, aiming to detect new physics beyond standard QED through symmetry tests in a leptonic system.

Contribution

It analyzes possible signals of CP and CPT violation in orthopositronium decay within the Standard-Model Extension framework.

Findings

Identifies decay correlations sensitive to CP and CPT violation.

Proposes experimental signatures for symmetry violations in positronium decay.

Discusses the implications for physics beyond the Standard Model.

Abstract

Positronium, the electron-positron bound state, is described to a good approximation by pure QED. The states of positronium have definite values of C and P. Consequently, positronium is an attractive system for the investigation of possible violations of the discrete symmetries in the leptonic sector. We discuss signals for CP and CPT violation in the decay of spin-polarized orthopositronium and show where such correlations might arise in the context of the Standard-Model Extension.