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

• Autor(a) principal: Santos, S. P. Amor dos
• Data de Publicação: 2015
• Outros Autores: Carvalho, J., Fiolhais, M. C. N., Galhardo, B., Veloso, F., Wolters, H., ATLAS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/109103; https://doi.org/10.1140/epjc/s10052-015-3685-1

Studies of the spin, parity and tensor couplings of the Higgs boson in the H → ZZ∗ → 4 , H → WW∗ → eνμν and H → γγ decay processes at the LHC are presented. The investigations are based on 25 fb−1 of pp collision data collected by the ATLAS experiment at √ s = 7 TeV and √ s = 8 TeV. The Standard Model (SM) Higgs boson hypothesis, corresponding to the quantum numbers J P = 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∗ → 4 and H → WW∗ → eνμν decays, the tensor structure of the interaction between the spin-0 boson and the SM vector bosons 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.