We study the associated production of a very light pseudoscalar Higgs boson
with a pair of charginos. The novel signature involves a pair of charged
leptons from chargino decays and a pair of photons from the pseudoscalar Higgs
boson decay, plus large missing energy at the LHC and ILC. The signal may help
us to distinguish the NMSSM from MSSM, provided that the experiment can resolve
the two photons from the decay of the pseudoscalar Higgs boson.Comment: pages, 2 figures; to appear in Proceedings of SUSY06, the 14th
International Conference on Supersymmetry and the Unification of Fundamental
Interactions, UC Irvine, California, 12-17 June 200