SUPERSYMMETRIC HIGGS-BOSON DECAYS INTO SCALAR QUARKS - QCD CORRECTIONS

In supersymmetric theories, the decays of the neutral CP-even and CP-o dd as well as the charged Higgs bosons into scalar quarks, in particul ar into top and bottom squarks, can be dominant if they are kinematica lly allowed. We calculate the QCD corrections to these decay modes in the minimal supersymmetric extension of the standard model, including all quark mass terms and squark mixing. These corrections turn out to be rather large, altering the decay widths by an amount which can be l arger than 50%. The corrections can be either positive or negative, an d depend strongly on the mass of the gluino. We also discuss the QCD c orrections to the decays of heavy scalar quarks into light scalar quar ks and Higgs bosons.