CP-odd and CP-even Weak-Basis Invariants in the Presence of Vector-Like Quarks

TL;DR

This paper introduces a minimal set of weak-basis invariants in a Standard Model extension with a vector-like quark, revealing new CP violation effects and implications for baryogenesis and high-energy collisions.

Contribution

It proposes new CP-odd invariants in an extended SM with a vector-like quark, enabling analysis of CP violation beyond the SM and at higher energy scales.

Findings

CP-odd invariants of lower order than in SM

CP violation observable above electroweak scale

Implications for baryogenesis and high-energy collisions

Abstract

We propose a minimal set of weak-basis invariants in an extension of the SM where one up-type isosinglet vector-like quark is introduced, which allows us to obtain all the physical content of the CKM matrix. We present CP-odd invariants of lower order in mass than the one in the SM, which may have important consequences for Baryogenesis. We study the extreme chiral limit, where the two lightest generations have vanishing mass, showing that in this extension, contrary to the SM, CP violation can be observed in collisions much above the electroweak scale.