PandaX Limits On Light Dark Matter With Light Mediator In The Singlet Extension Of MSSM

The Standard Model of particle physics is one of the most successful theory in this world,however,it still has some problems which can not be solved such as the Dark Matter(DM)issue.Plenty of evidences showed the presence of dark matter which is widely accepted by physicists and lots of theoretical and experimental studies have been done.On the one hand,many theoretical models of dark matter are proposed include SUSY models which can give several dark matter candidates.WIMP is the most promising DM candidate which can give correct DM relic density and explain the large scale structures of the Universe,but it could not explain the small scale structures of the Universe.On the other hand,there are a lot of experiments based on different principles with the purpose of searching dark matter.Though they haven't found the traces of dark matter,their data could constrain the models.Researches showed that dark matter with proper self-interactions can explain the small scale structures of the Universe.Using the latest PandaX limits on the light dark matter with a light mediator,we check their implication on the parameter space of the general singlet extension of MSSM(without Z3 symmetry),which can have a sufficient DM self-interaction to solve the small-scale structure problem.We find that the PandaX limits can tightly constrain the parameter space,depending on the coupling ? between the singlet and doublet Higgs fields.For the singlet extension of MSSM with Z3 symmetry,the so-called NMSSM,we also demonstrate the PandaX constraints on its parameter space,which gives a light DM with the correct relic density but without sufficient self-interaction to solve the small-scale structure problem.We find that in NMSSM,the GeV dark matter with a sub-GeV mediator is tightly constrained.