Supersymmetry, flavor physics and dark matter

In this talk, I first discuss $b\to d$, $b\to s$ and $s\to d$ transitions including time-dependent CP asymmetries in $B_d \to \phi K_s$ and Re ($\epsilon^{'}/\epsilon_K$). Then I show that the decay $B_s \to \mu^+ \mu^-$ is useful to distinguish various SUSY breaking mechanisms. I will also describe some possible connections between B physics and cosmology: (i) B physics and electroweak baryogenesis within SUSY models, and (ii) the correlation between the neutralino dark matter scattering and $B (B_s \to \mu^+ \mu^-)$. In particular, we point out that the current upper bound on $B (B_s \to \mu^+ \mu^-)$ form CDF and D0 collaborations can constrain the spin-independent neutralino scattering cross section more strongly than the CDMS bound.