  Identification of beyond-standard-models including WIMP dark matter is
studied in four particle final state with a W boson pair and a WIMP pair at the
International Linear Collider. Models with different spin structures give
distinguishable production angle distributions. After the mass determination in
each model, the production angle is reconstructed using the four momentum of W
bosons with a back-to-back constraint. Three models of Inert Higgs,
Supersymmetry and Little Higgs are considered. Discrimination power at 200 fb
and 40 fb signal cross section with 500 fb-1 luminosity at sqrt(s) = 500 GeV is
obtained.
