Higgs-mediated K→πνν in the MSSM at large tanβ

We analyze the impact of Higgs-mediated amplitudes on the rare decays KL→π0νν and K+→π+νν in the MSSM with large tanβ and general flavor mixing. We point out that, going beyond the minimal flavor violation hypothesis, Z-penguin amplitudes generated by charged-Higgs exchange can induce sizable modifications of K→πνν rates. Interestingly, these effects scale as tan4β at the amplitude level. For large values of tanβ, this mechanism allows deviations from the SM expectations even for tiny (Cabibbo-Kobayashi-Maskawa-type) off-diagonal mixing terms in the right-handed squark sector