Measurement of SUSY Masses via Cascade Decays for SPS 1a

If R-parity conserving supersymmetry exists below the TeV-scale, newparticles will be produced and decay in cascades at the LHC. The lightestsupersymmetric particle will escape the detectors, thereby complicating thefull reconstruction of the decay chains. In this paper we expand on existingmethods for determining the masses of the particles in the cascade fromendpoints of kinematical distributions. We perform scans in the mSUGRAparameter space to delimit the region where this method is applicable. From theexamination of theoretical distributions for a wide selection of mass scenariosit is found that caution must be exerted when equating the theoreticalendpoints with the experimentally obtainable ones. We provide analytic formulaefor the masses in terms of the endpoints most readily available. Complicationsdue to the composite nature of the endpoint expressions are discussed inrelation to the detailed analysis of two points on the SPS~1a line. Finally wedemonstrate how a Linear Collider measurement can improve dramatically on theprecision of the masses obtained.Comment: 57 pages, several figures, some of which should be viewed/printed in colour. v2: version accepted for publicatio