Probing the extended Higgs sector through rare b→sμ⁺μ⁻ transitions

Abstract

We study the constraints on the contribution of new physics in the form of scalar/pseudoscalar operators to the average forward-backward asymmetry ‹A_FB› of muons in B→Kμ⁺μ⁻ and the longitudinal polarization asymmetry A_LP of muons in B_s→μ⁺μ⁻. We find that the maximum possible value of ‹A_FB› allowed by the present upper bound on B(B_s→μ⁺μ⁻) is about 1% at 95% C.L. and hence will be very difficult to measure. On the other hand, the present bound on B(B_s→μ⁺μ⁻) fails to put any constraints on A_LP, which can be as high as 100% even if B(B_s→μ⁺μ⁻) is close to its standard model prediction. The measurement of A_LP will be a direct evidence for an extended Higgs sector, and combined with the branching ratio B(B_s→μ⁺μ⁻) it can even separate the new physics scalar and pseudoscalar contributions.