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

Aad, G. and Abbott, B. and Abdallah, J. and Abdinov, O. and Aben, R. and Krasznahorkay, Attila and Nagai, Yoshikazu and Pásztor, Gabriella and Tóth, József (2015) Study of (W/Z)H production and Higgs boson couplings using H→ W W ∗ decays with the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS (8). ISSN 1126-6708

Preview

Text 1506.06641.pdf Available under License Creative Commons Attribution. Download (1MB) | Preview

Abstract

A search for Higgs boson production in association with a W or Z boson, in the H→ W W ∗ 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 W H 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 W H 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 W H and ZH signal yield to the Standard Model expectation, μV H , is found to be μV H = 3.0+1.3 −1.1 (stat.)+1.0 −0.7 (sys.) for the Higgs boson mass of 125.36 GeV. The W H and ZH production modes are also combined with the gluon fusion and vector boson fusion production modes studied in the H → W W ∗ → `ν`ν decay channel, resulting in an over- all observed significance of 6.5 standard deviations and μggF+VBF+VH = 1.16+0.16 −0.15(stat.)+0.18 −0.15(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+0.26 −0.20.

Actions (login required)

Edit Item