In the next-to minimal supersymmetric standard model (NMSSM) the lightest supersymmetric particle (LSP) is a candidate for the dark matter (DM) in the universe. It is a mixture from the various gauginos and Higgsinos and can be bino-, Higgsino- or singlino-dominated. These different scenarios are investigated in detail in this letter and compared with the sensitivity of future direct DM search experiments, where we use an efficient sampling technique of the parameter space. We find that LSPs with a significant amount of Higgsino and bino admixture will have cross sections in reach of future direct DM experiments, so the background from coherent neutrino scattering is not yet limiting the sensitivity. Both, the spin-dependent (SD) and spin-independent (SI) searches are important, depending on the dominant admixture. If the predicted relic density is too low, additional dark matter candidates are needed, in which case the LSP direct dark matter searches loose sensitivity of the reduced LSP density. This is taken into account for expected sensitivity. The most striking result is that the singlino-like LSP has regions of parameter space with cross sections below the “neutrino floor”, both for SD and SI interactions. In this region the background from coherent neutrino scattering is expected to be too high, in which case the NMSSM will evade discovery via direct detection experiments.
C. Beskidt, W. Boer, D. Kazakov, et. al.
Mon, 6 Mar 17
Comments: 23 pages, 6 figures