  Semi-leptonic and leptonic decays of B-mesons are important probes for
testing SM and theories beyond it because of their relative cleanliness and far
less theoretical uncertainties. In semi-leptonic decays based on quark level
transition $b \to s \tau^+ \tau^-$ apart from branching ratio one can study
many other (possible) observables associated with final state leptons like,
lepton pair Forward Backward asymmetry, lepton polarization asymmetries etc.
But as proposed recently if we can tag the B-meson than one can measure the
polarization asymmetries of both the leptons. Here we will study the
polarization asymmetries of both the final state leptons in SM and Minimal
Supersymmetric Extension (MSSM) to it.
