Present Status and Future Tests of the Higgsino-Singlino Sector in the NMSSM

Abstract

The light higgsino-singlino scenario of the NMSSM allows to combine a naturally small $\mu$ parameter with a good dark matter relic density. Given the new constraints on spin-dependent and spin-independent direct detection cross sections in 2016 we study first which regions in the plane of chargino- and LSP-masses below 300 GeV remain viable. Subsequently we investigate the impact of searches for charginos and neutralinos at the LHC, and find that the limits from run I do not rule out any additional region in this plane. Only the HL-LHC at 3000 fb${}^{-1}$ will test parts of this plane corresponding to higgsino-like charginos heavier than 150 GeV and relatively light singlinos, but notably the most natural regions with lighter charginos seem to remain unexplored.

Comments: 16 pages, 2 figures, added discussion on the remaining fine-tuning