Status of low mass LSP in SUSY

TL;DR

This review discusses the viability of light neutralino and sneutrino dark matter candidates in SUSY models, considering collider, direct, and indirect detection constraints, and explores models where these candidates remain feasible.

Contribution

It provides a comprehensive overview of the current status and constraints on low mass LSPs in various SUSY frameworks, highlighting where they remain viable or are ruled out.

Findings

Light neutralino is largely ruled out in cMSSM.

pMSSM with non-thermal cosmology allows light neutralino.

Light RH sneutrino remains a viable dark matter candidate.

Abstract

In this article we review the case for a light ($< m_{h_{125}}/2$) neutralino and sneutrino being a viable Dark Matter (DM) candidate in Supersymmetry(SUSY). To that end we recapitulate, very briefly, three issues related to the DM which impact the discussions : calculation of DM relic density, detection of the DM in Direct and Indirect experiments and creation /detection at the Colliders. In case of SUSY, the results from Higgs and SUSY searches at the colliders also have implications for the DM mass and couplings. In view of the constraints coming from all these sources, the possibility of a light neutralino is all but ruled out for the constrained MSSM : cMSSM. The pMSSM, where the gaugino masses are not related at high scale, is also quite constrained and under tension in case of thermal DM and will be put to very stern test in the near future in Direct Detection (DD) experiments as well as by the LHC analyses. However in the pMSSM with modified cosmology and hence non-thermal DM or in the NMSSM, a light neutralino is much more easily accommodated. A light RH sneutrino is also still a viable DM candidate although it requires extending the MSSM with additional singlet neutrino superfields. All of these possibilities can be indeed tested jointly in the upcoming SUSY-electroweakino and Higgs searches at the HL/HE luminosity LHC, the upcoming experiments for the Direct Detection (DD) and indirect detection for the DM as well as the high precision electron-positron colliders under planning.