Blind spots for neutralino dark matter in the NMSSM

TL;DR

This paper analyzes the conditions under which neutralino dark matter in the NMSSM evades direct detection, identifying new blind spots due to Higgs-singlet mixing and their implications for Higgs observables.

Contribution

It analytically identifies new blind spots in the NMSSM for neutralino dark matter detection, highlighting the role of Higgs-singlet mixing and scalar interference effects.

Findings

Blind spots depend on Higgs-singlet mixing effects.

Blind spots can occur for any singlino-Higgsino composition.

Destructive interference can suppress detection cross-section.

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 singlino-Higgsino 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.