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

TL;DR

This paper compares the residual quantum effects of heavy sparticles on the Higgs-bottom quark coupling in the MSSM and NMSSM, highlighting potential for future collider measurements to probe supersymmetry and distinguish models.

Contribution

It provides a comparative analysis of supersymmetric QCD effects on the hbb coupling in MSSM and NMSSM, emphasizing the broader residual effects possible in NMSSM.

Findings

Residual effects can exceed 20% in hbb coupling.

NMSSM allows for a broader range of residual effects.

Future measurements could distinguish models based on these effects.

Abstract

If the sparticles are relatively heavy (a few TeV) while the Higgs sector is not so heavy ($m_A$ 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 hbb 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 hbb coupling, the NMSSM can allow for a much broader region of such effects. Since these residual effects can be over 20% for the hbb coupling (and thus over 40% for the ratio $Br(h->bb)/Br(h->\tau \tau)), future measurements may unravel the effects of heavy sparticles or even distinguish the two models.