Probing the seesaw scale with gravitational waves

Understand

The $U(1)_{B-L}$ gauge symmetry is a promising extension of the standard model of particle physics, which is supposed to be broken at some high energy scale.

• Associated with the $U(1)_{B-L}$ gauge symmetry breaking, right-handed neutrinos acquire their Majorana masses and then tiny light neutrino masses are generated through the seesaw mechanism.
• In this paper, we demonstrate that the first-order phase transition of the $U(1)_{B-L}$ gauge symmetry breaking can generate a large amplitude of stochastic gravitational wave (GW) radiation for some parameter space of the model, which is detectable in future experiments.
• Therefore, the detection of GWs is an interesting strategy to probe the seesaw scale which can be much higher than the energy scale of collider experiments.