Are there discrete symmetries in relativistic quantum mechanics?

Abstract

Since the CPT theorem was introduced in the 20th century, it has been one of the most important ongoing projects in particle physics. The CPT invariance helps to indicate if there are discrete symmetries in relativistic quantum mechanics (RQM), the answer to this question is ambiguous. This paper will mainly explain the answers via the timeline and point out misnomers and some missing concepts. We claim the answer to Are There Discrete Symmetries in Relativistic Quantum Mechanics is “yes, but no, no and yes again”. The most recent experiment shows the violation of CPT invariance is only [Formula: see text].