Baryogenesis from a primordial lepton asymmetry
Abstract
There are two ways in which a primordial lepton asymmetry may be turned into a baryon asymmetry at the weak scale. The first is well known in the literature and works in equilibrium. Here we introduce the second, which operates if the electroweak phase transition is first order. Tau leptons are partially reflected off the bubble walls resulting in a hypercharge transport into the symmetric phase. Because leptons do not interact strongly, their thermal length is relatively large and leads to a baryon number consistent with observation. Since the resulting asymmetry is comparable to that produced if the phase transition is second order, we conclude that the baryon number induced by a primordial lepton asymmetry is independent of the way it is processed at the weak scale.
 Publication:

Physics Letters B
 Pub Date:
 September 1994
 DOI:
 10.1016/03702693(94)914109
 arXiv:
 arXiv:hepph/9401234
 Bibcode:
 1994PhLB..335..179A
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 20 pages standard LaTeX, 5 Figures available on request, Report RAL93103