Asymmetries in rare radiative leptonic and semileptonic decays of B mesons

The time-dependent and time-independent CP asymmetries $ A_{CP}^{B_q^0 to f} left( tau right) $ A_{CP}^{B_q^0 to f} left( tau right) and $ A_{CP}^{B_q^0 to f} left( {hat s} right) $ A_{CP}^{B_q^0 to f} left( {hat s} right) for rare semileptonic and radiative leptonic decays of B mesons are calculated by the method of helicity amplitudes. The sensitivity of CP asymmetries to various extensions of the Standard Model that have an operator basis that is identical to the operator basis of the Standard Model is investigated. It is shown that, by combining information about the form of the charge lepton asymmetry A _FB at small values of the square of the invariant dilepton mass and information about the average value of the time-dependent CP asymmetry, one can in principle determine the relative phases of the Wilson coefficients C _7γ , C _9V , and C _10A in the effective Hamiltonian for b → {d, s}ℓ⁺ℓ⁻ transitions.