Decoupling behaviour of O(m_t^4) corrections to the h^0 self-couplings

The decoupling behaviour of the leading one-loop Yukawa-coupling contributions of O(m_t^4) to the lightest MSSM Higgs boson self-couplings, when the top-squarks are heavy as compared to the electroweak scale, are discussed. As shown analytically and numerically, the large corrections can almost completely be absorbed into the h^0-boson mass and therefore, the h^0 self-couplings remain similar to the coupling of the SM Higgs boson for a heavy top-squark sector.