Higher-order determination of transitional CP violation

Determine whether CP violation can be dynamically generated inside the bubble wall of the top-philic Type-III two-Higgs-doublet model by incorporating higher-order finite-temperature corrections beyond the one-loop treatment and solving for the corresponding bubble-wall configuration.

Background

The paper investigates transitional CP violation (TCPV), in which the Lagrangian and the vacua outside the bubble wall are CP conserving but a CP-odd field configuration develops within the wall during the electroweak phase transition. A viable TCPV solution requires a negative eigenvalue of the CP-odd fluctuation operator and a corresponding nonlinear three-field bounce with nonzero CP-odd field.

No such negative mode or viable TCPV branch is found in the pseudoscalar-mass regions examined using the one-loop finite-temperature effective potential. The authors nevertheless note that higher-order corrections could modify both the CP-odd fluctuation operator and the bubble-wall solution, leaving the possibility of TCPV beyond the present approximation unresolved.