Study of (W/Z)H production and Higgs boson couplings using H→ WW∗ decays with the ATLAS detector

Allbrooke, B M M, Asquith, L, Cerri, A, Chavez Barajas, C A, De Santo, A, Salvatore, F, Santoyo Castillo, I, Suruliz, K, Sutton, M R, Vivarelli, I and The ATLAS Collaboration, et al. (2015) Study of (W/Z)H production and Higgs boson couplings using H→ WW∗ decays with the ATLAS detector. Journal of High Energy Physics, 2015 (137). ISSN 1029-8479

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Abstract

A search for Higgs boson production in association with a W or Z boson, in the H→WW∗ decay channel, is performed with a data sample collected with the ATLAS detector at the LHC in proton-proton collisions at centre-of-mass energies √s=7 TeV and 8 TeV, corresponding to integrated luminosities of 4.5 fb−1 and 20.3 fb−1, respectively. The WH production mode is studied in two-lepton and three-lepton final states, while two- lepton and four-lepton final states are used to search for the ZH production mode. The observed significance, for the combined WH and ZH production, is 2.5 standard deviations while a significance of 0.9 standard deviations is expected in the Standard Model Higgs boson hypothesis. The ratio of the combined WH and ZH signal yield to the Standard Model expectation, μVH, is found to be μVH = 3.0− 1.1+ 1.3(stat.)− 0.7+ 1.0(sys.) for the Higgs boson mass of 125.36 GeV. The WH and ZH production modes are also combined with the gluon fusion and vector boson fusion production modes studied in the H → WW∗ → ℓνℓν decay channel, resulting in an overall observed significance of 6.5 standard deviations and μggF + VBF + VH = 1. 16 − 0.15+ 0.16(stat.)− 0.15+ 0.18(sys.). The results are interpreted in terms of scaling factors of the Higgs boson couplings to vector bosons (κV) and fermions (κF); the combined results are: |κV| = 1.06− 0.10+ 0.10, |κF| = 0. 85− 0.20+ 0.26.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups: Experimental Particle Physics Research Group
Subjects: Q Science > QC Physics
Depositing User: Billy Wichaidit
Date Deposited: 27 Apr 2017 10:59
Last Modified: 27 Apr 2017 11:06
URI: http://sro.sussex.ac.uk/id/eprint/67538

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Project NameSussex Project NumberFunderFunder Ref
ATLASG0275STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCILST/I006048/1