PT Journal AU Edelhauser, L Porod, W Singh, RK TI Spin discrimination in three-body decays SO Journal of High Energy Physics JI J. High Energy Phys. PY 2010 BP 053 EP 31pp VL 08 IS 8 DI 10.1007/JHEP08(2010)053 LA English DE Beyond Standard Model; Supersymmetric Standard Model AB The identification of the correct model for physics beyond the Standard Model requires the determination of the spin of new particles. We investigate to which extent the spin of a new particle X can be identified in scenarios where it decays dominantly in three-body decays X -> f (f) over barY. Here we assume that Y is a candidate for dark matter and escapes direct detection at a high energy collider such as the LHC. We show that in the case that all intermediate particles are heavy, one can get information on the spins of X and Y at the LHC by exploiting the invariant mass distribution of the two standard model fermions. We develop a model-independent strategy to determine the spins without prior knowledge of the unknown couplings and test it in a series of Monte Carlo studies. ER