Our wall as the origin of CP violation

TL;DR

This paper explores the hypothesis that our universe's CP violation originates from a domain wall in a brane world scenario, analyzing conditions for significant CP phases and effects of wall coexistence.

Contribution

It introduces a novel idea that the universe's CP violation may stem from domain walls and provides methods to estimate CP violation in such brane configurations.

Findings

CP violation can be of order one or suppressed on the wall.

Coexistence of CP-conserving walls can still lead to CP violation.

A useful approximation method for double-wall CP violation estimation.

Abstract

A possibility that the origin of the CP violation in our world is a domain wall itself, on which we are living, is investigated in the context of the brane world scenario. We estimate the amount of the CP violation on our wall, and show that either of order one or suppressed CP phases can be realized. An interesting case where CP is violated due to the {\it coexistence} of the walls, which conserve CP individually, is also considered. We also propose a useful approximation for the estimation of the CP violation in the double-wall background.