Dark matter constraints and the neutralino sector of the scNMSSM

Abstract

The neutralino sector of the semi-constrained next-to-minimal supersymmetric standard model is explored under recent experimental constraints, with special attention to dark matter (DM) limits. The effects of the upper and lower bounds of dark matter relic density and recent direct detection constraints on spin-independent and -dependent cross-sections are thoroughly analyzed. Particularly, we show which regions of the parameter space are ruled out due to the different dark matter constraints and the corresponding model-specific parameters: $λ, κ, A_λ$, and $A_κ$. We analyze all annihilation and co-annihilation processes (with heavier neutralinos and charginos) that contribute to the dark matter relic density. The mass components of the dark matter candidate, the lightest neutralino $\tildeχ_1^0$, are studied, and the decays of heavy neutralinos and charginos, especially $\tildeχ_2^0$ and $\tildeχ_1^+$, into the lightest neutralino are examined. We impose semi-universal boundary conditions at the Grand Unified Theory scale and require a moderate range of $\tanβ \lesssim 10$. We find that the allowed parameter space is associated with a heavy mass spectrum in general and that the lightest neutralino is mostly Higgsino with a mass range that resides mostly between 1000 and 1500 GeV. However, smaller mass values can be achieved if the DM candidate is bino-like or singlino-like.