BARYOGENESIS AT THE ELECTROWEAK SCALE

The generation of the baryon asymmetry of the universe is considered i n the standard model of the electroweak theory with simple extensions of the Higgs sector. The propagation of quarks of masses up to about 5 GeV are considered, taking into account their markedly different disp ersion relations due to propagation through the hot electroweak plasma . It is shown that the contribution of the b quark to the baryon asymm etry can be comparable to that for the t quark considered earlier.