The degenerate scenario in the NMSSM: Direct singlino-like neutralino searches with a gravitino LSP

TL;DR

This paper explores a two-component dark matter model within the NMSSM where a nearly degenerate gravitino LSP and singlino-like neutralino NLSP allow for high reheating temperatures and evade BBN bounds, with implications for direct detection.

Contribution

It introduces a degenerate scenario in the NMSSM with a gravitino LSP and neutralino NLSP, highlighting the viability of singlino-like neutralinos for dark matter detection.

Findings

Degenerate gravitino and neutralino masses evade BBN constraints.

Singlino-like neutralinos are consistent with all current constraints.

Model supports high reheating temperatures for thermal leptogenesis.

Abstract

A two-component dark matter model is studied adopting the degenerate scenario in the R-parity conserving NMSSM. The gravitino LSP and the neutralino NLSP are extremely degenerate in mass, avoiding the BBN bounds and obtaining a high reheating temperature for thermal leptogenesis to work. In this model both gravitino (absolutely stable) and neutralino (quasi-stable) contribute to dark matter, and direct detection searches for neutralino are discussed. Points that survive all the constraints correspond to a singlino-like neutralino.