Searches for the Zγ decay mode of the Higgs boson and for new high-mass resonances in pp collisions at √s=13 TeV with the ATLAS detector

• Autor(a) principal: Santos, S. P. Amor dos
• Data de Publicação: 2017
• Outros Autores: Fiolhais, M. C. N., Galhardo, B., Veloso, F., Wolters, H., ATLAS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Texto Completo: https://hdl.handle.net/10316/108236; https://doi.org/10.1007/JHEP10(2017)112
• topic: Hadron-Hadron scattering (experiments); Higgs physics

This article presents searches for the Z decay of the Higgs boson and for narrow high-mass resonances decaying to Z , exploiting Z boson decays to pairs of electrons or muons. The data analysis uses 36.1 fb1 of pp collisions at p s = 13 recorded by the ATLAS detector at the CERN Large Hadron Collider. The data are found to be consistent with the expected Standard Model background. The observed (expected | assuming Standard Model pp ! H ! Z production and decay) upper limit on the production cross section times the branching ratio for pp ! H ! Z is 6.6. (5.2) times the Standard Model prediction at the 95% con dence level for a Higgs boson mass of 125.09 GeV. In addition, upper limits are set on the production cross section times the branching ratio as a function of the mass of a narrow resonance between 250 GeV and 2.4 TeV, assuming spin- 0 resonances produced via gluon-gluon fusion, and spin-2 resonances produced via gluongluon or quark-antiquark initial states. For high-mass spin-0 resonances, the observed (expected) limits vary between 88 fb (61 fb) and 2.8 fb (2.7 fb) for the mass range from 250 GeV to 2.4 TeV at the 95% con dence level.