Strong Sphalerons and Electroweak Baryogenesis

We analyze the spontaneous baryogenesis and charge transport mechanisms suggested by Cohen, Kaplan and Nelson for baryon asymmetry generation in extended versions of electroweak theory. We find that accounting for non-perturbative chirality-breaking transitions due to strong sphalerons reduces the baryonic asymmetry by the factor $(m_t/\pi T)^2$ or $\alpha_W$, provided those processes are in thermal equilibrium.