Electroweak baryogenesis between broken phases in multi-step phase transition

Possibility of electroweak baryogenesis (EWBG) via multi-step phase transition (PT) is considered. We investigate the EWBG between SU (2) broken phases in the second step PT of the two-step PT. The produced baryon number asymmetry is evaluated using a prototypical model with a SU (2) charged CP-odd scalar field. We show that the second step PTs where the sphaleron rate is possible to be un-suppressed before the PTs, which can reproduce the sufficient baryon number asymmetry. Our studies can be adapted to models with extra SU (2) scalar fields. We discuss specific models suitable for our scenario. & COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons .org /licenses /by /4 .0/). Funded by SCOAP3.