Supersonic electroweak baryogenesis: achieving baryogenesis for fast bubble walls

Abstract

Standard electroweak baryogenesis in the context of a first order phase transition is effective in generating the baryon asymmetry of the universe if the broken phase bubbles expand at subsonic speed, so that CP asymmetric currents can diffuse in front of the wall. Here we present a new mechanism for electroweak baryogenesis which operates for supersonic bubble walls. It relies on the formation of small bubbles of the symmetric phase behind the bubble wall, in the broken phase, due to the heating of the plasma as the wall passes by. We apply the mechanism to a model in which the Higgs field is coupled to several singlets, and find that enough baryon asymmetry is generated for reasonable values of the parameter space.

Unified explanation for dark matter and electroweak baryogenesis with direct detection and gravitational wave signatures

“…[11]. Were this the case, the evaluation of the baryon asymmetry would be controversial [49]. This particularly applies to the EWPTs marked as filled circles in Fig.…”

Bubble expansion and the viability of singlet-driven electroweak baryogenesis

“…More recently, an interesting scenario was presented in ref. [107], in which bubbles can expand quickly enough to significantly reheat the plasma inside the bubble. Secondary bubbles can then nucleate near which transport-driven baryogenesis can occur.…”

Stability of cosmological detonation fronts

“…Except in the limit λ → 0, the friction saturates at high velocities, and the detonation approaches the speed of light at a finite value of η, which is given by Eq. (37). Below this value, we have no detonations, and the wall runs away.…”

“…An interesting feature of detonations is the fact that the reheating behind the wall may surpass the critical temperature (provided that the latent heat is high enough for the given amount of supercooling). An application of this fact is the interesting idea of supersonic electroweak baryogenesis [37]. In this scenario, small bubbles of the symmetric phase nucleate in the superheated brokensymmetry phase behind the wall.…”