Alternative Approach to $B^- \to \eta^{\prime} K^-$ Branching Ratio Calculation

Since the calculation of $BR(B^- \to \eta^{\prime} K^-)$ in the framework of QCD improved factorization method, developed by Beneke et al., leads to numerical values much below the experimental data, we include two different contributions, in an alternative way. First, we find out that the spectator hard-scattering mechanism increases the $BR$ value with almost 50%, but the predictions depend on the combined singularities in the amplitude convolution. Secondly, by adding SUSY contributions to the Wilson coefficients, we come to a $BR$ depending on three parameters, whose values are constrained by the experimental data.