In SUSY, a light dark matter is usually accompanied by light scalars to
achieve the correct relic density, which opens new decay channels of the SM
like Higgs boson. Under current experimental constraints including the latest
LHC Higgs data and the dark matter relic density, we examine the status of a
light neutralino dark matter in the framework of NMSSM and confront it with the
direct detection results of CoGeNT, CDMS-II and LUX. We have the following
observations: (i) A dark matter as light as 8 GeV is still allowed and its
scattering cross section off the nucleon can be large enough to explain the
CoGeNT/CDMS-II favored region; (ii) The LUX data can exclude a sizable part of
the allowed parameter space, but still leaves a light dark matter viable; (iii)
The SM-like Higgs boson can decay into the light dark matter pair with an
invisible branching ratio reaching 30% under the current LHC Higgs data, which
may be tested at the 14 TeV LHC experiment.Comment: 18 pages, 4 figure