Probing mild-tempered neutralino dark matter through top-squark production at the LHC

Abstract

The lightest neutralino, assumed to be the lightest supersymmetric particle, is proposed to be a dark matter (DM) candidate for the mass range around O(100) GeV. Constraints from various direct dark matter detection experiments and Planck measurements exclude a substantial region of parameter space of minimal supersymmetric standard model (MSSM). However, a “mild-tempered” neutralino with dominant bino composition with a little admixture of Higgsino is found to be a viable candidate for DM. Within the MSSM framework, we revisit the allowed region of parameter space which is consistent with all existing constraints from direct detection experiments. Regions of parameters that are not sensitive to direct detection experiments, known as “blind spots”, are also revisited. Complimentary to the direct detection of DM particle, mildtempered neutralino scenario is explored at the LHC with the center of mass energy √ s=13 TeV through the top-squark pair production, and its subsequent decays with the SM like Higgs boson in the final state. Our considered channel is found to be very sensitive also to the blind spot scenario. A reasonable signal sensitivity is achieved using the cut-based method for the high luminosity options 300 fb−1 and 3000 fb−1, which are further improved by applying the multi-variate analysis (MVA) technique. ∗[email protected] †[email protected] ‡[email protected] 1 ar X iv :2 10 3. 09 81 0v 1 [ he pph ] 1 7 M ar 2 02 1