Limiting Majoron self-interactions from Gravitational waves experiments

Understand

We show how Majoron models may be tested/limited in gravitational waves experiments.

• In particular, the Majoron self-interaction potential may induce a first order phase transition, producing gravitational waves from bubble collisions.
• We dubbed such a new scenario {\it violent Majoron model}, because it would be associated to a violent phase transition in the early Universe.
• Sphaleron constraints can be avoided if the global $U(1)_{B-L}$ is broken at scales lower than the electroweak scale, provided that the B-L spontaneously breaking scale is lower than $10\, {\rm TeV}$ in order to satisfy the cosmological mass density bound.