1996/01/24 by Tomislav Prokopec, Robert Brandenberger, Prokopec, Tomislav +3
Computer Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Astrophysics (astro-ph) #Computational Physics and Python Applications #Cosmology and Gravitation Theories #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #astro-ph #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9601327
20 pages, LaTeX, no figures
arxiv created 1996/01/24 · openalex publication_date 1996/01/24 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We investigate whether baryogenesis is possible at a second order electroweak phase transition. We find that under rather general conditions, the departure from thermal equilibrium is suppressed by the expansion rate of the Universe, and hence baryon production is also suppressed by the expansion rate. We conclude that if no additional sources of departure from thermal equilibrium such as topological defects are present, then electroweak baryogenesis is ruled out if the phase transition is second order or crossover. However, a non-vanishing net baryon to entropy ratio \it is generated, and we provide both upper and lower bounds for the result. Our technique is also applicable to other baryogenesis mechanisms taking place during and immediately after a second order phase transition. We estimate the lowest value of the transition energy scale for which the resulting baryon to entropy ratio might be large enough to explain observations.