Escaping the Large Fine Tuning and Little Hierarchy Problems in the Next   to Minimal Supersymmetric Model and h-> aa Decays
  We demonstrate that the NMSSM can have small fine tuning and modest light stop mass while still evading all experimental constraints. For small tan(beta) [large tan(beta)], the relevant scenarios are such that there is always (often) a SM-like Higgs boson that decays to two lighter -- possibly much lighter -- pseudoscalar Higgses. 
Radovan Dermisek and John F. Gunion