QCD Corrections to Supersymmetric Higgs Boson Production: The Role of Squark Loops

We calculate the two-loop QCD corrections to the production of the neutral supersymmetric Higgs bosons via the gluon fusion mechanism at hadron colliders, including the contributions of squark loops. To a good approximation, these additional contributions lead to the same QCD corrections as in the case where only $t$ and $b$ quark loops are taken into account. The inclusion of both squark loops and QCD corrections increase the Higgs production cross sections significantly over the lowest order rates.