The Right-Handed Slepton Bulk Regions for Dark Matter in the Generalized Minimal Supergravity (GmSUGRA)

We study the light right-handed slepton bulk regions for dark matter from the Generalized Minimal Supergravity (GmSUGRA) in the Minimal Supersymmetric Standard Model (MSSM). In our comprehensive numerical studies, we show that $\mathcal{R_{\tilde{\phi}}}\gtrsim10\%$ is a conservative criteria to formulate bulk region, where $\mathcal{R_{\tilde{\phi}}}\equiv({m_{\tilde{\phi}}-m_{\tilde{\chi}_1^0}})/{m_{\tilde{\chi}_1^0}}$. For right-handed stau as the Next to the Lightest Supersymmetric Partcile (NLSP), we find a large viable parameter space, consistent with the current LHC constraints, Planck2018 dark matter relic density bounds, and direct bounds on neutralino-nucleons scattering cross-section that naturally supports the right-handed stau bulk regions for dark matter. In particular, the upper bounds on the masses of the Lightest Supersymmetric Particle (LSP) neutralino and right-handed stau are about 120.4 GeV and 138 GeV, respectively. This bulk region may be beyond the current LHC reach and could be probed at LUX-ZEPLIN, a next-generation dark matter direct detection experiment, the Future Circular Collider (FCC-ee) at CERN, and the Circular Electron Positron Collider (CEPC). However, the scenario with the right-handed selectron as the NLSP is excluded by the LHC supersymmetry searches.