Individual and Combined Measurements of the Spin and Parity Properties of the Higgs Boson Using the ATLAS Detector

Measurements by the ATLAS Experiment of the spin and parity quantum numbers of the Higgs boson are presented. The Standard Model hypothesis (spin 0, even parity) is compared with various alternatives using the diphoton, WW*, and ZZ* decay channels. All measurements use the dataset collected at the LHC in 2012 at an 8 TeV center-of-mass energy with an integrated luminosity of 20.7 inverse femtobarns. The ZZ* decay also uses the dataset collected in 2011 at a 7 TeV center-of-mass energy with an integrated luminosity of 4.6 inverse femtobarns. Observations are compatible with the Standard Model quantum numbers for spin and parity. Alternative hypotheses, for spin-parity numbers of 0-, 1+, 1-, and 2+, are excluded at confidence levels exceeding 97.8%. These results constitute evidence in support of the spin 0 nature of the Higgs boson.