Study of the spin and parity of the Higgs boson in diboson decays with the ATLAS detector

ATLAS COLLABORATION, G. AAD, M.T. DOVA ET AL

EUROPEAN PHYSICAL JOURNAL C - PARTICLES AND FIELDS

SPRINGER

Lugar: Berlin; Año: 2015

1434-6044

Studies of the spin, parity and tensor couplings of the Higgs boson in the H→ZZ∗→4ℓ and H→γγ decay processes at the LHC are presented. The investigations are based on 25/fb collision data collected by the ATLAS experiment at 7 and 8 TeV. The Standard Model (SM) Higgs boson hypothesis, corresponding to the quantum numbers JP=0+ , is tested against several alternative spin scenarios, including non-SM spin-0 and spin-2 models with universal and non-universal couplings to fermions and vector bosons. All tested alternative models are excluded in favour of the SM Higgs boson hypothesis at more than 99.9% confidence level. Using the H→ZZ∗→4ℓ and H→WW∗→eνμν interaction in the spin-0 hypothesis is also investigated. The observed distributions of variables sensitive to the non-SM tensor couplings are compatible with the SM predictions and constraints on the non-SM couplings are derived.