Searching for new physics in leptonic B decays

It is shown that compared to that of SM, the branching ratio of B → ℓ⁺ℓ⁻ can be enhanced by an order of magnitude in a model II 2HDM. In SUSY model it can be enhanced by three order of magnitude and even reach the experimental bounds. violation of this process is shown to be even as large as 40% for B_d in very large range of parameter space. For B_s it can be as large as 3%. The SM prediction is and for B_d and B_s respectively