Physics

Electron

Lepton

MAJORANA

Baryon asymmetry

LIGO

Mathematics

Parameter space

Particle physics

Statistics

Neutrino

Symmetry breaking

Nuclear physics

Gravitational wave

Astrophysics

Leptogenesis

Physical review. D/Physical review. D.

We analyze the classically scale-invariant $B\ensuremath{-}L$ model in the context of resonant leptogenesis with the recently proposed mass-gain mechanism. The $B\ensuremath{-}L$ symmetry breaking in this scenario is associated with a strong first-order phase transition that gives rise to detectable gravitational waves (GWs) via bubble collisions. The same $B\ensuremath{-}L$ symmetry breaking also gives Majorana mass to right-handed neutrinos inside the bubbles, and their out-of-equilibrium decays can produce the observed baryon asymmetry of the Universe via leptogenesis. We show that the current LIGO-VIRGO limit on stochastic GW background already excludes part of the $B\ensuremath{-}L$ parameter space, complementary to the collider searches for heavy ${Z}^{\ensuremath{'}}$ resonances. Moreover, future GW experiments like Einstein Telescope and Cosmic Explorer can effectively probe the parameter space of leptogenesis over a wide range of the $B\ensuremath{-}L$ symmetry-breaking scales and gauge coupling values.

Gravitational wave pathway to testable leptogenesis