Blind spots for neutralino dark matter in the NMSSM

Abstract

Spin-independent cross-section for neutralino dark matter scattering off nuclei is investigated in the NMSSM. Several classes of blind spots for direct detection of singlinoHiggsino dark matter are analytically identified, including such that have no analog in the MSSM. It is shown that mixing of the Higgs doublets with the scalar singlet has a big impact on the position of blind spots in the parameter space. In particular, this mixing allows for more freedom in the sign assignment for the parameters entering the neutralino mass matrix, required for a blind spot to occur, as compared to the MSSM or the NMSSM with decoupled singlet. Moreover, blind spots may occur for any composition of a singlino-Higgsino LSP. Particular attention is paid to cases with the singlet-dominated scalar lighter than the 125 GeV Higgs for which a vanishing tree-level spin-independent scattering cross-section may result from destructive interference between the Higgs and the singlet-dominated scalar exchange. Correlations of the spin-independent scattering cross-section with the Higgs observables are also discussed.

Minimal model of gravitino dark matter

“…A quick look at Eq. (12) shows that such a large cross section is obtained for a high reheating temperature or small values of F (and thus a light gravitino), explaining the shape of the green region in Fig. 1.…”

“…At the supersymmetric (SUSY) level, the authors of Ref. [12] showed that the well-tempered neutralino-which was the most robust supersymmetric candidate in recent years-is now severely constrained by the last results of LUX [6]. A wino-like neutralino is also severely constrained by the latest indirectdetection searches released by the Fermi Collaboration [3].…”

Present status and future tests of the higgsino-singlino sector in the NMSSM

“…Still, such a mostly singlino-like LSP is good dark matter candidate [18] since its relic density can be reduced to the observed value via various processes like a mostly singletlike pseudoscalar in the s-channel, chargino exchange in the t-channel or co-annihilation. Furthermore a mostly singlino-like LSP can easily satisfy limits from direct and indirect dark matter detection experiments; its spin-independent direct detection cross section can even fall below the neutrino floor [19,20].…”

“…Another search channel is W H (where H is the Higgs boson of the Standard Model), where one assumes a χ 0 2 decay of the form χ 0 2 → H + χ 0 1 , still concentrating on the leptonic W ( * ) decay. Previous studies of constraints on, phenomenological aspects and future prospects of the light singlino scenario in the NMSSM have been performed in [15,20,. Here we proceed as follows: in the plane defined by the chargino (charged higgsino) mass M χ ± 1 < 300 GeV and the (mostly singlino-like) LSP mass…”

Enhanced Higgs associated production with a top quark pair in the NMSSM with light singlets

“…The compatibility with the LUX constraints is the reason for choosing negative value of M 1 in the benchmarks because µM 1 < 0 allows for some cancellations in the Higgs coupling to LSP which results in smaller SI scattering cross-section [70]. Additional suppression of the SI scattering cross-section may originate from destructive interference between the contributions to the SI scattering amplitude from the Higgs and the light singlet-scalar exchange which are of comparable size if Higgs-singlet mixing is non-negligible as in the present scenario [71]. For somewhat larger tan β SI scattering cross-section could be also suppressed by effects of destructive interference with the amplitude generated by MSSM-like Higgs exchange [72].…”