Kinematic Cusps with Two Missing Particles II: Cascade Decay Topology

Three-step cascade decays into two invisible particles and two visible particles via two intermediate on-shell particles develop cusped peak structures in several kinematic distributions. We study the basic properties of the cusps and endpoints in various distributions and demonstrate that the masses of the missing particles and the intermediate particles can be determined by the cusp and endpoint positions. Effects from realistic considerations such as finite decay widths, longitudinal boost of the parent particle, and spin correlations are shown to be under control for the processes illustrated.