Residual effects of heavy sparticles in the bottom quark Yukawa coupling: A comparative study for the MSSM and NMSSM

Abstract: If the sparticles are relatively heavy (a few TeV) while the Higgs sector is not so heavy ( is not so large), the Higgs boson Yukawa couplings can harbor sizable quantum effects of sparticles and these large residual effects may play a special role in probing supersymmetry at foreseeable colliders. In this work, focusing on the supersymmetric QCD effects in the coupling (h is the lightest CP-even Higgs boson), we give a comparative study for the two popular supersymmetric models: the MSSM and NMSSM. While for both models the supersymmetric QCD can leave over large residual quantum effects in coupling, the NMSSM can allow for a much broader region of such effects. Since these residual effects can be over 20% for the coupling (and thus over 40% for the ratio ), future measurements may unravel the effects of heavy sparticles or even distinguish the two models. [Copyright &y& Elsevier]