Higgs Mixing in the NMSSM and Light Higgsinos

TL;DR

This paper investigates Higgs mixing effects in the NMSSM, showing how light Higgsinos and singlet-doublet mixing can explain the Higgs mass and influence Higgs couplings, consistent with current collider data.

Contribution

It provides a detailed analysis of Higgs mixing in the NMSSM, highlighting conditions for light Higgsinos and their impact on Higgs properties and collider constraints.

Findings

Light Higgsinos are favored by Higgs mixing scenarios.

Singlet-doublet mixing can raise the Higgs mass without large stop mixing.

Higgs coupling to photons can be significantly affected by charged-higgsino loops.

Abstract

We explore the effects of Higgs mixing in the general next-to-minimal supersymmetric Standard Model (NMSSM). Extended to include a gauge singlet, the Higgs sector can naturally explain the observed Higgs boson mass in TeV scale supersymmetry without invoking large stop mixing. This is particularly the case when the singlet scalar is light so that singlet-doublet mixing increases the mass of the SM-like Higgs boson. In such a case the Higgs mixing has interesting implications following from the fact that the higgsino mass parameter and the singlet coupling to Higgs bilinear crucially depend on the Higgs boson masses and mixing angles. For the mixing compatible with the current LHC data on the Higgs signal rates, the higgsinos are required to be relatively light, around or below a few hundred GeV, as long as the heavy doublet Higgs boson has a mass smaller than about 250\sqrt{\tan\beta} GeV and the singlet-like Higgs boson is consistent with the LEP constraint. In addition, the Higgs coupling to photons can receive a sizable contribution of either sign from the charged-higgsino loops combined with singlet-doublet mixing.