Sizable CP Violation in the Bosonized Standard Model

TL;DR

This paper derives an effective bosonic action for the Standard Model using the worldline method, revealing significant CP violation in the bosonic sector that surpasses previous bounds and is not suppressed by light quark Yukawa couplings.

Contribution

It introduces a novel calculation of CP-violating operators in the bosonic sector of the Standard Model using the worldline approach, highlighting larger-than-expected CP violation effects.

Findings

CP violation in the bosonic sector is sizable and not suppressed by light quark Yukawa couplings.

The effective CP violation exceeds bounds set by the Jarlskog determinant.

The worldline method effectively derives CP-violating operators in the Standard Model.

Abstract

Using the worldline method, we derive an effective action of the bosonic sector of the Standard Model by integrating out the fermionic degrees of freedom. The CP violation stemming from the complex phase in the CKM matrix gives rise to CP-violating operators in the one-loop effective action in the next-to-leading order of a gradient expansion. We calculate the prefactor of the appropriate operators and give general estimates of CP violation in the bosonic sector of the Standard Model. In particular, we show that the effective CP violation for weak gauge fields is not suppressed by the Yukawa couplings of the light quarks and is much larger than the bound given by the Jarlskog determinant.