The question of the order of the electroweak phase transition is central to electroweak baryogenesis. Since the equilibrium description of particle phenomena is extremely accurate at electroweak temperatures, baryogenesis cannot typically occur at such low scales without the aid of phase transitions. For a continuous transition, the associated departure from equilibrium is still insufficient to lead to relevant baryon number production. However, for a first order transition, at a critical temperature the nucleation of bubbles of the true vacuum in the sea of false begins, and at a particular temperature below this, bubbles just large enough to grow nucleate. These are termed critical bubbles, and they expand, eventually filling all of space and completing the transition. As the bubble walls pass each point in space there is a significant departure from thermal equilibrium so that, if the phase transition is strongly enough first order, it is possible to satisfy the third Sakharov criterion.
The context is interesting, but fairly heavy. Spending some time chasing down and understanding some of the glancing references here might be a good way to provide some intellectual motivation and focus.
No comments:
Post a Comment