Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector
Name
Constraints on the.pdf
Size
1.74 MB
Format
Adobe PDF
Checksum (MD5)
be20c060516c06647602274ce9718dbd
Author(s)
Taylor, Frank E
Date Issued
July 2015
Journal
The European Physical Journal C
Publisher
Springer-Verlag
Citation
ATLAS Collaboration et al. “Constraints on the off-Shell Higgs Boson Signal Strength in the High-Mass ZZ and WW Final States with the ATLAS Detector.” The European Physical Journal C 75.7 (2015): n. pag. © 2015 CERN for the benefit of the ATLAS collaboration
Version
Final published version
Abstract
Measurements of the ZZ and WW final states in the mass range above the 2m[subscript Z] and 2m[subscript 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[subscript −1] at a collision energy of √s =8 TeV. Using the CLs 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[subscript H]/Γ
[superscript SM][subscript 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.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1140/epjc/s10052-015-3542-2
