EFFICIENT ELECTROWEAK BARYOGENESIS FROM LEPTON TRANSPORT

One mechanism for generating a baryon asymmetry at the electroweak pha se transition involves propagation of particle asymmetries generated b y reflection from the bubble walls into the unbroken phase. Hitherto a ttention has focussed on top quarks because of their large mass and th us effective scattering from bubble walls. In this paper we point out that leptons may be more efficient mediators of this type of electrowe ak baryogenesis, particularly for thicker bubble walls favored by pert urbative calculations. We carry out an analytic calculation of each st age of the mechanism and conclude it produces a baryon asymmetry compa tible with observations for a wide range of parameters.