Supersymmetric Electroweak Baryogenesis in the WKB approximation

Abstract

We calculate the baryon asymmetry generated at the electroweak phase transition in the minimal supersymmetric standard model, treating the particles in a WKB approximation in the bubble wall background. A set of diffusion equations for the particle species relevant to baryon generation, including source terms arising from the CP violation associated with the complex phase $δ$ of the $μ$ parameter, are derived from Boltzmann equations, and solved. The conclusion is that $δ$ must be $\gsim 0.1$ to generate a baryon asymmetry consistent with nucleosynthesis. We compare our results to several other recent computations of the effect, arguing that some are overestimates.

Figures (1)

• Figure 1: Contours of constant $\eta_{10}=10^{10}\eta$ in the plane of $m_2$ (the Wino mass) and $\mu$, in GeV, $v_{\rm wall}= 0.05$, $0.1$ and $0.2$, $\tan\beta=2$, $\sin\delta=1$ and wall width $2w = 14/T$.