Electroweak baryogenesis with the vector-like quark model
  We study on the electroweak baryogenesis problem in the vector-like quark model. This model can add to the minimal standard model the extra CP-violation source which breaks CP spontaneously. Using charge transport mechanism suggested by Nelson et al, we can get the net hypercharge flux : $f_{Y} \sim 10^{-5}$. This result could nicely explain the present baryon to entropy ratio : $\rho_{B}/s \sim 10^{-9}$. 
Tomoko Uesugi