Do new data on B⁺→τ⁺ν_τ decays point to an early discovery of supersymmetry at the LHC?

Abstract

The recent Belle and BABAR measurements of the branching ratio of B⁺→τ⁺ν_τ indicate a significant deviation from the standard model prediction. We demonstrate that this measurement has a serious impact on models with minimal flavor violation involving a charged Higgs boson, ruling out a large portion of the currently allowed parameter space. In the constrained minimal supersymmetric standard model, this creates a tension between the measurements of B⁺→τ⁺ν_τ and the anomalous magnetic moment of the muon, unless tanβ is small, μ>0, and A₀ takes a large negative value. In fact, a very small region of the parameter space of this model, with small values of m₀ and m_1/2, survives all the constraints at 95% C.L. It is remarkable that this specific region is still consistent with the lightest supersymmetric particle as the dark matter. Moreover, it predicts observable supersymmetric signals in the early runs of the LHC, even perhaps at 7 TeV. We also show that a consistent explanation for the deviation of the B⁺→τ⁺ν_τ branching ratio from the standard model can be achieved in a nonuniversal Higgs-mass model, which could also predict early signals of supersymmetry at the LHC.