Higgsino asymmetry and direct-detection constraints of light dark matter in the NMSSM with non-universal Higgs masses

In this study, we analyze the direct-detection constraints of light dark matter in the next-to minimal supersymmetric standard model (NMSSM) with non-universal Higgs masses (NUHM); we specially focus on the correlation between higgsino asymmetry and spin-dependent (SD) cross section. We draw the following conclusions. (i) The SD cross section is proportional to the square of higgsino asymmetry in dark matter in the NMSSM-NUHM, and hence, it is small for highly singlino-dominated dark matter. (ii) The higgsino-mass parameter is smaller than approximately in the NMSSM-NUHM due to the current muon g-2 constraint, but our scenario with light dark matter can still be alive under current constraints including the direct detection of dark matter in the spindependent channel. (iii) With a sizeable higgsino component in the light dark matter, the higgsino asymmetry and SD cross section can also be sizeable, but dark matter relic density is always small; thus, it can escape the direct detections. (iv) Light dark matter in the - and Z-funnel annihilation channels with sufficient relic density can be covered by future LUX-ZEPLIN (LZ) 7-ton in SD detections. (v) The spin-independent (SI) cross section is dominated by - and -exchanging channels, which can even cancel each other in some samples, leaving an SI cross section smaller by a few orders of magnitude than that of one individual channel.

Automated summary

This study focuses on direct-detection constraints of light dark matter in the NMSSM-NUHM, specifically looking at the correlation between higgsino asymmetry and SD cross section. It is found that the SD cross section is proportional to the square of higgsino asymmetry, leading to smaller values for highly singlino-dominated dark matter. Additionally, scenarios with significant higgsino components in light dark matter can still survive under current constraints, with the possibility of detection by future experiments like the LUX-ZEPLIN 7-ton detector.