Higgs boson flavor-changing neutral decays into bottom quarks in supersymmetry

We analyze the maximum branching ratios for the Flavor Changing Neutral Current (FCNC) decays of the neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) into bottom quarks, h → bs̄ (h = h 0,H0, A0). We consistently correlate these decays with the radiative B-meson decays (b → sγ). A full-fledged combined numerical analysis is performed of these high-energy and low-energy FCNC decay modes in the MSSM parameter space. Our calculation shows that the available data on B(b → sγ) severely restricts the allowed values of B(h → bs̄). While the latter could reach a few percent level in fine-tuned scenarios, the requirement of naturalness reduces these FCNC rates into the modest range B (h → bs̄) ∼ 10-4-10 -3. We find that the bulk of the MSSM contribution to B(h → bs̄) could originate from the strong supersymmetric sector. The maximum value of the FCNC rates obtained in this paper disagree significantly with recent (over-)estimates existing in the literature. Our results are still encouraging because they show that the FCNC modes h → bs̄ can be competitive with other Higgs boson signatures and could play a helpful complementary role to identify the supersymmetric Higgs bosons, particularly the lightest CP-even state in the critical LHC mass region mh0 ≃ 90-130 GeV. © SISSA/ISAS 2004.