Associated Production of Higgs Bosons with Scalar Quarks at Future Hadron and e^+e^- Colliders

We analyze the production of neutral Higgs particles in association with the supersymmetric scalar partners of the third generation quarks at future high--energy hadron colliders [upgraded Tevatron, LHC] and $e^+e^-$ linear machines [including the $\gamma \gamma$ option]. In the Minimal Supersymmetric extension of the Standard Model, the cross section for the associated production of the lightest neutral $h$ boson with the lightest top squark pairs can be rather substantial at high energies. This process would open a window for the measurement of the $h \tilde{t} \tilde{t}$ coupling, the potentially largest coupling in the supersymmetric theory.