Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector
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 predi...
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todo:paper_14346044_v75_n7_p1_Aad2023-10-03T16:15:06Z Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector Aad, G. 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 √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. © CERN for the benefit of the ATLAS collaboration 2015. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14346044_v75_n7_p1_Aad |
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Universidad de Buenos Aires |
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I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
description |
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 √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. © CERN for the benefit of the ATLAS collaboration 2015. |
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JOUR |
author |
Aad, G. |
spellingShingle |
Aad, G. Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector |
author_facet |
Aad, G. |
author_sort |
Aad, G. |
title |
Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector |
title_short |
Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector |
title_full |
Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector |
title_fullStr |
Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector |
title_full_unstemmed |
Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector |
title_sort |
constraints on the off-shell higgs boson signal strength in the high-mass zz and ww final states with the atlas detector |
url |
http://hdl.handle.net/20.500.12110/paper_14346044_v75_n7_p1_Aad |
work_keys_str_mv |
AT aadg constraintsontheoffshellhiggsbosonsignalstrengthinthehighmasszzandwwfinalstateswiththeatlasdetector |
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1807315754826072064 |