Non-Universal Gaugino Masses in the NMSSM

TL;DR

This paper explores how non-universal gaugino masses in the NMSSM can ease electroweak symmetry-breaking constraints, allowing for higgsino-like dark matter and predicting testable superpartner masses at future colliders.

Contribution

It demonstrates that relaxing gaugino mass universality in the NMSSM broadens viable parameter space and enables a higgsino-like dark matter candidate consistent with observed Higgs mass.

Findings

Higgsino can be the lightest SUSY particle with correct relic density.

Many superpartners, including gluinos, could be within reach of a 100 TeV collider.

Non-universality relaxes electroweak symmetry-breaking restrictions.

Abstract

The Next-to-Minimal Supersymmetric Standard Model (NMSSM) provides a natural framework to realize a low-scale supersymmetric (SUSY) model, where a singlet superfield is added to the minimal model to generate a SUSY-scale higgsino mass term with its vacuum expectation value. Due to the presence of the extra singlet field, the vacuum conditions to realize the correct electroweak symmetry-breaking become fairly restrictive especially if we impose universality conditions at the unification scale. In this paper, we show that a non-universal gaugino mass spectrum can significantly relax this restriction even though the scalar masses and trilinear couplings are subject to universality conditions. With the gaugino non-universality, we find that higgsino can be the lightest SUSY particle and its thermal relic abundance can reproduce the observed dark matter density in a wide range of parameter space in which the 125~GeV Higgs-boson mass is obtained. This higgsino-like dark matter may be probed in direct detection experiments. We also find that there is an upper bound on the masses of supersymmetric particles in this scenario, and many model points predict colored particles such as gluino to be within the reach of a future 100~TeV collider. Implications for no-scale/gaugino-mediation models are also discussed.