Lepton polarization and forward-backward asymmetries in b→sτ+τ-

We study the spin polarizations of both τ leptons in the decay b→sτ+τ-. In addition to the polarization asymmetries involving a single τ, we construct asymmetries for the case where both polarizations are simultaneously measured. We also study forward-backward asymmetries with polarized τ's. We find that a large number of asymmetries are predicted to be large, > or approx. 10%. This permits the measurement of all Wilson coefficients and the b-quark mass, thus allowing the standard model (SM) to be exhaustively tested. Furthermore, there are many unique signals for the presence of new physics. For example, asymmetries involving triple-product correlations are predicted to be tiny within the SM, O(10-2). Their observation would be a clear signal of new physics