Electroweak Phase Transition and Gravitational Waves in the Type-II Seesaw Model

Abstract

The type-II seesaw model is a possible candidate for simultaneously explaining non-vanishing neutrino masses and the observed baryon asymmetry of the Universe. In this work, we study in detail the pattern of phase transition and the gravitational wave production of this model. We find a strong first-order electroweak phase transition generically prefers positive Higgs portal couplings and a light triplet below $\sim 550$ GeV. In addition, we find the gravitational wave yield generated during the phase transition would be at the edge of BBO sensitivity and could be further examined by Ultimate-DECIGO.

Comments: v1: 34 pages, 2 tables, 8 figures; v2: update references