Z₂-singlino dark matter in a portal-like extension of the minimal supersymmetric standard model

Abstract

We propose a Z 2 -stabilised singlino (χ) as a dark matter candidate in extended and R-parity violating versions of the supersymmetric standard model. χ interacts with visible matter via a heavy messenger field S, which results in a supersymmetric version of the Higgs portal interaction. The relic abundance of χ can account for cold dark matter if the messenger mass satisfies M S < ∼ 10 4 GeV. Our model can be implemented in many realistic supersymmetric models such as the NMSSM and nMSSM. PACS numbers: 12.60.Jv, 98.80.Cq, 95.35.+d

PeV-scale dark matter as a thermal relic of a decoupled sector

“…In this letter, we explore this class of scenarios, focusing on hidden sectors that are thermally decoupled and, therefore, never reach equilibrium with the visible sector. In this case, the DM freezes-out of chemical equilibrium within its own sector, unaffected by SM dynamics.So long as the hidden sector consists entirely of SM singlets, renormalizable interactions between the SM and the DM can proceed only through the following gauge singlet operators: H † H, B µν , and H † L, known as the Higgs portal [18,[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], the vector portal [18,41], and the lepton portal [18,42], respectively. If the couplings that facilitate such interactions are sufficiently small, the hidden and visible sectors will be decoupled from one another, potentially altering the thermal history of the universe (see, e.g., ).If, by coincidence, a hidden sector DM candidate has a GeV-TeV scale mass and weak-scale couplings, it will behave in many respects like a typical WIMP, although possibly with very feeble interactions with the SM.…”

keV warm dark matter via the supersymmetric Higgs portal

“…The form of SUSY breaking may be determined at the LHC from the pattern of SUSY particle masses. Here we present a new WDM candidate, the Z 2 -singlino, in a portal-like extension of the minimal supersymmetric (SUSY) standard model (MSSM) [12,13] in which the stability of the WDM particle is ensured by a Z 2 -parity. The Z 2 -singlino was previously introduced to provide a stable dark matter candidate in R-parity violating SUSY models [12].…”

“…Here we present a new WDM candidate, the Z 2 -singlino, in a portal-like extension of the minimal supersymmetric (SUSY) standard model (MSSM) [12,13] in which the stability of the WDM particle is ensured by a Z 2 -parity. The Z 2 -singlino was previously introduced to provide a stable dark matter candidate in R-parity violating SUSY models [12]. Here we will show that, in a different region of its parameter space, the model provides a dark matter particle which is necessarily warm and with the right properties to explain non-singular galaxy halos and to alleviate the galaxy substructure and low angular momentum problems of CDM models.…”

“…We also impose an additional Z 2 symmetry under which χ is odd, while all other fields are even. The effective superpotential after integrating out S is given by [12]…”

“…Eqn. (12) then provides an upper limit on M χ in the case with an explicit SUSY χ mass. If we assume a dynamical suppression of Q by at most a factor 10 3 , then the largest value of Q consistent with observations is ≈ 10 10 eV/cm 3 /(km/s) 3 .…”