Determination of Spin and CP-Eigenvalue of the Higgs Boson with ATLAS

A possibility to prove spin and CP-eigenvalue of a Standard Model (SM) Higgs boson is presented. We exploit angular correlations in the subsequent decay H $\to$ ZZ $\to$ 4l (muons or electrons). We compare the angular distributions of the leptons originating from the SM Higgs with those resulting from decays of hypothetical particles with differing quantum numbers. This decay channel is the most promising one for Higgs searches at the LHC. We restrict our analysis to the use of the Atlas-detector which is one of two multi-purpose detectors at the upcoming 14 TeV proton-proton-collider (LHC) at CERN. By applying a fast simulation of the Atlas detector it can be shown that these correlations will be measured sufficiently well to prove consistency with the parameters of the Standard Model Higgs. Although the method is valid for all Higgs masses, we focus on the mass range above 200 GeV, where the branching ratio to ZZ is high enough to perform the measurement at an integrated luminosity of 100 fb$^{-1}$.