New Higgs effects in B-physics in supersymmetry with general flavour mixing

We investigate the effect of general flavour mixing among squarks on the rare decays B¯→Xsγ, B¯s→μ+μ− and B¯s-Bs mixing beyond the leading order in perturbation theory. We include all large tanβ-enhanced corrections whilst also taking into account the effects of general flavour mixing on the uncorrected quark mass matrix and SU(2)L×U(1)Y breaking. For B¯s→μ+μ− and B¯s-Bs mixing we find that, in analogy to B¯→Xsγ, there appears a focusing effect which can reduce the contribution due to the δRR (and the δLL) insertion by up to a factor of two at large tanβ and μ>0. A dependence on δLR and δRL, that otherwise cancels to first order in the mass insertion approximation, is also reintroduced. Taking into account the current experimental bounds on ΔMBs and BR(B¯s→μ+μ−), we find that the insertions δRL and δRR can be significantly constrained compared to bounds obtained from B¯→Xsγ only.