  Within the framework of a constrained Minimal Supersymmetric Standard Model
(cMSSM) augmented by an MSSM singlet-pair sector to account for the non-zero
neutrino masses by inverse seesaw mechanism, the lightest supersymmetric
particle (LSP) can be a mixed sneutrino with mass as small as 50 GeV,
satisfying all existing constraints, thus qualifying as a light dark matter
candidate. We study the possibility of the lightest neutral Higgs boson in this
model decaying invisibly into a pair of sneutrino LSPs, thereby giving rise to
novel missing energy signatures at the LHC. We perform a two-parameter global
analysis of the LHC Higgs data available till date to determine the optimal
invisible Higgs branching fraction in this scenario, and obtain a
$2\sigma(1\sigma)$ upper limit of 0.23 (0.12). A detailed cut-based analysis is
carried out thereafter, demonstrating the viability of our proposed signal
vis-a-vis backgrounds at the LHC.
