@article{OPUS4-14961,
  title     = {Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector},
  series = {European Physical Journal C: Particles and Fields},
  volume    = {75},
  journal   = {European Physical Journal C: Particles and Fields},
  number    = {7},
  organization    = {ATLAS Collaboration},
  doi       = {10.1140/epjc/s10052-015-3542-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149615},
  pages     = {335},
  year      = {2015},
  abstract  = {Measurements of the ZZ and WW final states in the mass range above the 2m\(_Z\) and 2m\(_W\) thresholds provide a unique opportunity to measure the off-shell coupling strength of the Higgs boson. This paper presents constraints on the off-shell Higgs boson event yields normalised to the Standard Model prediction (signal strength) in the ZZ→4ℓ, ZZ→2ℓ2ν and WW→eνμν final states. The result is based on pp collision data collected by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 20.3 fb\(^{-1}\) at a collision energy of \(\sqrt {s}\)=8 TeV. Using the CL\(_S\) method, the observed 95 \% confidence level (CL) upper limit on the off-shell signal strength is in the range 5.1-8.6, with an expected range of 6.7-11.0. In each case the range is determined by varying the unknown gg→ZZ and gg→WW background K-factor from higher-order quantum chromodynamics corrections between half and twice the value of the known signal K-factor. Assuming the relevant Higgs boson couplings are independent of the energy scale of the Higgs boson production, a combination with the on-shell measurements yields an observed (expected) 95 \% CL upper limit on Γ\(_H\)/Γ\(^{SM}_{H}\) in the range 4.5-7.5 (6.5-11.2) using the same variations of the background K-factor. Assuming that the unknown gg→VV background K-factor is equal to the signal K-factor, this translates into an observed (expected) 95 \% CL upper limit on the Higgs boson total width of 22.7 (33.0) MeV.},
  language  = {en}
}