In the Next-to-Minimal Supersymemtric Standard Model (NMSSM), one of the
neutral Higgs scalars (CP-even or CP-odd) may be lighter than half of the
SM-like Higgs boson. In this case, the SM-like Higgs boson h can decay into
such a light scalar pair and consequently the diphoton and ZZ signal rates at
the LHC will be suppressed. In this work, we examine the constraints of the
latest LHC Higgs data on such a possibility. We perform a comprehensive scan
over the parameter space of the NMSSM by considering various experimental
constraints and find that the LHC Higgs data can readily constrain the
parameter space and the properties of the light scalar, e.g., at 3 σ
level this light scalar should be highly singlet dominant and the branching
ratio of the SM-like Higgs boson decay into the scalar pair should be less than
about 30%. Also we investigate the detection of this scalar at various
colliders. Through a detailed Monte Carlo simulation we find that under the
constraints of the current Higgs data this light scalar can be accessible at
the LHC-14 with an integrated luminosity over 300 fb−1.Comment: Accepted by JHE