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

Understand

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 $\sim550$ 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.