Atomic EDM

The coupling between an axion-like particle (ALP) and the Higgs boson can potentially enhance the electroweak phase transition to be strongly first order. Local electroweak baryogensis, which has been ruled out for the traditioanl Higgs operator, can be effective for the operator that couples the ALP with various anomalies. This paper investigates such a scenario with various ways to probe.

It has been known the electroweak baryogenesis (EWBG) in the minimal SM is suppressed by the large damping rate of the quark quasiparticle in the thermal plasma, due to the strong QCD interaction. Old literatures proposed a possibility that lepton scattering may be capable of generating enough baryon asymmetry since the damping rate could be much smaller. Is this really the case? This paper proposes a model that mimic the SM quark sector with chiral leptons. We investigate the thermodynamics in detail and concluded that it could be only marginally OK to generate the baryon asymmetry from a lepton sector with CKM-like structure.