Relic density of dark matter in the NMSSM

TL;DR

This work presents a public computational framework that calculates the relic density of dark matter in the NMSSM by interfacing NMHDECAY for spectrum and constraints with micrOMEGAs for neutralino annihilation and coannihilation processes, incorporating Higgs-sector radiative corrections via an effective Lagrangian. It systematically explores MSSM-like, bino LSP, mixed bino/higgsino, and singlino LSP scenarios, showing that the NMSSM's richer Higgs sector opens additional annihilation pathways, particularly through Higgs resonances and light Higgs states. The study demonstrates that NMSSM relic densities can satisfy the WMAP window in multiple regimes, including resonance-enhanced bino annihilation and coannihilation for singlino-dominated LSPs, with mixed bino/higgsino regions naturally aligning with the observed density. The results highlight the importance of Higgs-sector corrections, extended Higgs states, and singlino dynamics for accurate relic-density predictions and point to distinctive collider implications and future refinements incorporating flavor constraints.

Abstract

We present a code to compute the relic density of dark matter in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). Dominant corrections to the Higgs masses are calculated with NMHDECAY as well as theoretical and collider constraints. All neutralino annihilation and coannihilation processes are then computed with an extended version of micrOMEGAs, taking into acount higher order corrections to Higgs vertices. We explore the parameter space of the NMSSM and consider in particular the case of a bino LSP, of a mixed bino-higgsino LSP and of a singlino LSP. As compared to the MSSM, neutralino annihilation is often more efficient as it can take place via (additional) Higgs resonances as well as annihilation into light Higgs states. Models with a large singlino component can be compatible with WMAP constraints.

Figures (8)

• Figure 1: Contour plots for $\Omega h^2 = 0.02$, $0.0945 < \Omega h^2 < 0.1287$ (WMAP constraint) and $\Omega h^2 = 1$ in the $\mu$, $M_2$ plane for $\lambda=0.1$, $\kappa=0.1$, $\tan\!\beta=5$, $A_\lambda=500$ GeV and $A_\kappa=0$. The hatched region is excluded by LEP constraints on charginos.
• Figure 2: a) $\Omega h^2$ as a function of $\mu$ for $\lambda=0.1, \kappa=0.1, A_\lambda=500$ GeV, $A_\kappa=0, M_2=230$ GeV, $\tan\!\beta=5$ (full) and $\tan\!\beta=2,20$ (dash). b) Relative contribution of the main annihilation channels for the case $\tan\!\beta=5$. Here $VV$ includes both $WW$ and $ZZ$ channels and $qq$ is the sum over all the quarks.
• Figure 3: Region in the $\lambda, \kappa$ plane for which $0.0945 < \Omega h^2 < 0.1287$ (blue) for $\mu=700$ GeV, $M_2=111$ GeV, $A_\lambda=500$ GeV, $A_\kappa=0$, $\tan\!\beta=5$ and contour curve for $\Omega h^2=1$ (red). The theoretically/experimentally excluded regions are also displayed: LEP Higgs exclusion (grey), Landau pole (vertical lines), negative Higgs mass squared (horizontal lines) and non-physical global minima of the scalar potential (black).
• Figure 4: a) $\Omega h^2$ vs $\lambda$ for $\mu=700$ GeV,$M_2=111$ GeV,$\kappa=0.01,0.1,0.5$, $A_\lambda=500$ GeV, $A_\kappa=0$ and $\tan\!\beta=5$. b) Relative contribution of the main annihilation channels for the case $\kappa=0.5$.
• Figure 5: $\Omega h^2$ vs $A_\lambda$ for $\mu=300$ GeV,$M_2=300$ GeV,$\kappa=0.1,\lambda=0.1, A_\kappa=-50$ GeV and $\tan\!\beta=5$. b) Masses of LSP, of scalars (dash) and pseudo-scalars (full) c) Relative contribution of the main annihilation channels.