Higgs-Portal Dark Matter in Nonlinear MSSM

TL;DR

This paper proposes a minimal extension to the nonlinear MSSM by adding a parity-odd singlet, enabling a Higgs-portal dark matter candidate consistent with a 125 GeV Higgs and addressing cosmological issues with gravitino dark matter.

Contribution

It introduces a new scalar singlet in the nonlinear MSSM framework, providing a viable Higgs-portal dark matter candidate and solving gravitino dark matter problems.

Findings

The scalar in the singlet superfield acts as Higgs-portal DM.

The model achieves a 125 GeV Higgs mass at tree level.

The scenario is consistent with multi-TeV SUSY breaking.

Abstract

Supersymmetric (SUSY) extension of the Standard Model (SM) is a primary candidate for new physics beyond the SM. If SUSY breaking scale is very low, for example, the multi-TeV range, and the SUSY breaking sector, except for the goldstino (gravitino), is decoupled from the low energy spectrum, the hidden sector effect in the minimal SUSY SM (MSSM) is well described by employing the goldstino chiral superfield ($X$) with the nilpotent condition of $X^2=0$. Although this so-called "nonlinear MSSM" (NL-MSSM) provides a variety of interesting phenomenologies, there is a cosmological problem that the lightest superpartner gravitino is too light to be the major component of the dark matter (DM) in our universe. To solve this problem, we propose a minimal extension of the NL-MSSM by introducing a parity-odd SM singlet chiral superfield ($\Phi$). We show that the interaction of the scalar component in $\Phi$ with the MSSM Higgs doublets is induced after eliminating F-component of the goldstino superfield and the lightest real scalar in $\Phi$ plays the role of the Higgs-portal DM. With a suitable choice of the model parameters, a successful Higgs-portal DM scenario can be realized while achieving the SM-like Higgs boson mass of 125 GeV from the tree-level Higgs potential through the multi-TeV SUSY breaking effect.