CP violation in QCD

Abstract

Among the parameters of QCD is one that results in CP violation when non-vanishing. This is closely related to possible quark mass terms. It is conventionally interpreted in terms of gauge field topology or alternatively in terms of phases in the quark masses. There is no experimental evidence for this parameter having a non-zero value, a puzzle for theories involving unification.

Comments: 11 pages, 9 figures, contribution to conference XIII Quark Confinement and the Hadron Spectrum - Confinement2018