Rare decays $B\to X_sl^+l^-$ and $B\to K^{(*)}l^+l^-$ in SM and beyond

Abstract

After a brief review of the inclusive and exclusive rare semileptonic decays of B mesons in the standard model (SM), an overview of recent theoretical developments in this field is given. New physics effects on various observables such as branching ratio, backward-forward asymmetry, polarization of lepton and CP violation in the decays are anlyzed in models beyond SM (supersymmetric models and two Higgs doublet models).