Some Studies On Supersymmetric Higgs And Dark Matter

Given the recent constraints from the dark matter(DM)direct detections,we examine a light GeV-scale(2-30 GeV)neutralino DM in the alignment limit of the Minimal Supersymmetric Standard Model(MSSM).In this limit without decoupling,the heavy CP-even scalar H plays the role of the Standard Model(SM)Higgs boson while the other scalar h can be rather light so that the DM can annihilate through the h resonance or into a pair of h to achieve the observed relic density.With the current collider and cosmological constraints,we find that such a light neutralino DM above 6 GeV can be excluded by the XENON-1T(2017)limits while the survivied parameter space below 6 GeV can be fully tested by the future germanium-based light dark matter detections(such as CDEX),by the Higgs coupling precison measurements or by the production process e~+e~-→hA at an electron-positron collider(Higgs factory).Also,we scrutinize the parameter space of the SM-like Higgs boson in the MSSM under current experimental constraints.The constraints are from(i)the precision electroweak data and various flavor observables;(ii)the direct 22 sep-arate ATLAS searches in Run-1;(iii)the latest LHC Run-2 Higgs data and tri-lepton search of electroweakinos.We perform a scan over the parameter space and find that the Run-2 data can further exclude a part of parameter space.For the properties of the SM-like Higgs boson,its gauge couplings further approach to the SM values with a deviation below 0.1%,while its Yukawa couplings hbˉb and hτ~+τ~-can still sizably differ from the SM predictions by several tens percent.