The charged-Higgs-boson contributions to the Wilson coecients C7 and C8, relevant for the
decay B ! Xs
, are discussed in supersymmetric models at large tan . These contributions
receive two-loop O(s tan) corrections by squark-gluino subloops, which a...
The charged-Higgs-boson contributions to the Wilson coecients C7 and C8, relevant for the
decay B ! Xs
, are discussed in supersymmetric models at large tan . These contributions
receive two-loop O(s tan) corrections by squark-gluino subloops, which are possibly large and
nondecoupling in the limit of heavy superpartners. In previous studies, the relevant two-loop
Feynman integrals were approximated by using an eective two-Higgs-doublet lagrangian. However,
this approximation is theoretically justied only when the typical supersymmetric scale MSUSY is
suciently larger than the electroweak scale mweak (mW;mt) and the mass of the charged-Higgs
boson mH. Here, we evaluate these two-loop integrals exactly and compare the results with the
existing, approximated ones. We then examine the validity of this approximation beyond the region
where it has been derived, i.e. for mH MSUSY and/or MSUSY mweak.