Spin sensitive variables for the products of supersymmetric particles

Abstract

Supersymmetry (SUSY) is a possible extension of the Standard Model, which predicts that each Standard Model fermion has a boson superpartner and each Standard Model boson has a fermion superpartner. The search for supersymmetry is one of the main topics for study with the Compact Muon Solenoid (CMS), a general purpose detector at the Large Hadron Collider (LHC) at CERN. In this thesis, particle spin measurement are studied through effects in angular correlations in the decay products of supersymmetric particles. A Lorentz invariant quantity, the invariant mass of decay products, has been used to build asymmetries to investigate these correlation effects. Two different supersymmetric decay chains, namely the decay of a squark via a neutralino-2 and the decay of a stop quark (partner of top quark) via a chargino-1, have been used as examples for this study We conclude that we can expect to extract spin information from the sparticles. The required amount of data depends on the supersymmetric particle mass spectrum. We have studied several final states, in order to have several measurements for the spin characterization of the supersymmetric paticles