LHC constraints on light neutralino dark matter in the MSSM

Abstract

Light neutralino dark matter can be achieved in the Minimal Supersymmetric Standard Model if staus are rather light, with mass around 100 GeV. We perform a detailed analysis of the relevant supersymmetric parameter space, including also the possibility of light selectons and smuons, and of light higgsino- or wino-like charginos. In addition to the latest limits from direct and indirect detection of dark matter, ATLAS and CMS constraints on electroweak-inos and on sleptons are taken into account using a "simplified models" framework. Measurements of the properties of the Higgs boson at 125 GeV, which constrain amongst others the invisible decay of the Higgs boson into a pair of neutralinos, are also implemented in the analysis. We show that viable neutralino dark matter can be achieved for masses as low as 15 GeV. In this case, light charginos close to the LEP bound are required in addition to light right-chiral staus. Significant deviations are observed in the couplings of the 125 GeV Higgs boson. These constitute a promising way to probe the light neutralino dark matter scenario in the next run of the LHC.Comment: 18 pages, 6 figures; matches version accepted for publication in Physics Letters

Testing the light dark matter scenario of the MSSM at the LHC

“…At this stage, we'd like to clarify the differences of our study from previous literatures [37] and [42,43]. In [37], the authors scanned the parameter space of the MSSM by relaxing the slepton masses to get the light DM scenario, which is quite similar to what we did in this work.…”

“…In [37], the authors scanned the parameter space of the MSSM by relaxing the slepton masses to get the light DM scenario, which is quite similar to what we did in this work. The main difference of the two works is that the authors of [37] used the package SModelS [78] to implement the constraints of the direct searches on the electroweak-inos and sleptons, while we do it by detailed simulations. Because the feasibility of the SModelS is based on certain assumptions (e.g.…”

“…Recent discussions on the light DM scenario concentrated on the complement of new experimental constraints, such as those from the 125 GeV Higgs data and the direct searches for sparticles at the LHC, and consequently the allowed parameter space of the scenario shrinks significantly [34][35][36][37][38][39][40][41]43]. For example, it was found that the lower bound of mχ0 1 could be improved from about 10 GeV to roughly 25 GeV after considering the searches for multi-τ plus large E miss T signal at the early stage of the LHC Run-I [34].…”

Testing the higgsino-singlino sector of the NMSSM with trileptons at the LHC

“…On the other hand, a dominantly higgsino-like (neutralino) LSP is a difficult candidate for dark matter: its annihilation cross section in the early universe is typically too large so that, assuming a standard cosmological evolution, its relic density today is too small to comply with the WMAP and Planck result Ωh 2 ∼ 0.1187. Moreover, its direct detection (nucleon) cross section is also too large [21,27] in view of the latest XENON100 results [28] unless the higgsino component is close to 100%.…”

“…There, the absence of significant excesses of events is interpreted in simplified models, motivated by the SUSY particle content of the Minimal SUSY extension of the Standard Model (MSSM) and assuming simple branching ratios and relations among masses. Interpretations of the present constraints from the trilepton channel in realistic versions of the MSSM have been performed in [18][19][20][21] (see [22][23][24] for the rôle of trilepton final states in some beyond-the-MSSM models).…”