Electroweak baryogenesis in the three-loop neutrino mass model with dark matter

Abstract

Baryon asymmetry of the Universe is evaluated in the model originally proposed by Aoki et al. [Phys. Rev. Lett. 102, 051805 (2009)PRLTAO0031-900710.1103/PhysRevLett.102.051805], where Majorana masses of neutrinos are generated via three-loop diagrams composed of additional scalar bosons including the dark matter candidate which is odd under an unbroken Z2 symmetry. In order for the model to include multiple CP-violating phases, we do not impose the softly broken Z2 symmetry imposed in the original model to avoid the flavor-changing neutral current at tree level. Instead, for simplicity, we assume the flavor alignment structure in the Yukawa interactions. We also simply assume the alignment structure in the Higgs potential so that the Higgs couplings coincide with those in the standard model at tree level. Under these phenomenological simplifications, the model still contains multiple CP-violating phases. By using destructive interferences among them, it is compatible with the stringent constraint from the electric dipole moment measurements to generate the observed baryon asymmetry along with the scenario of electroweak baryogenesis. We show a benchmark scenario which can explain neutrino mass, dark matter, and baryon asymmetry of the Universe simultaneously and can satisfy all the other available experimental data. Some phenomenological predictions of the model are also discussed. © 2023 authors. Published by the American Physical Society.