Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector

ATLAS Collaboration

doi:10.1140/epjc/s10052-015-3542-2

Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector

ATLAS Collaboration

iThemba Labs
Department of Physics
University of South Africa
Cadi Ayyad University
Moroccan Foundation for Advanced Science Innovation and Research (MAScIR)
Dep Física and CEFITEC of Faculdade de Ciências e Tecnologia
NOVA University Lisbon
CERN
Aix-Marseille Université
University of Oklahoma
Academia Sinica - Institute of Physics
Azerbaijan National Academy of Sciences
University of Amsterdam
Michigan State University
University of Toronto
Tel Aviv University
Technion-Israel Institute of Technology
Stockholm University
University of the Witwatersrand
National Institute for Nuclear Physics
York University Toronto
University of Udine
AGH University of Krakow
Brookhaven National Laboratory
Northern Illinois University
Ludwig Maximilian University of Munich
Rutherford Appleton Laboratory
University of Liverpool
University of Belgrade
Laboratório de Instrumentação e Física Experimental de Partículas
University of Granada
University of Bern
Boston University
Joint Institute for Nuclear Research
University of Rome La Sapienza
Lund University
The University of Tokyo
P.N. Lebedev Physical Institute of the Russian Academy of Sciences
University of Bologna
University of Victoria BC
Université Grenoble Alpes
Instituto de Física La Plata
Horia Hulubei National Institute of Physics and Nuclear Engineering
National Technical University of Athens
The University of Chicago
Columbia University
University of Birmingham

Research output: Contribution to journal › Article › peer-review

92 Scopus citations

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 √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.

Original language	English
Article number	335
Pages (from-to)	1-34
Number of pages	34
Journal	European Physical Journal C
Volume	75
Issue number	7
DOIs	https://doi.org/10.1140/epjc/s10052-015-3542-2
State	Published - 2015

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10.1140/epjc/s10052-015-3542-2

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@article{1bab32fa059d44c1845df77b85e1c4fa,

title = "Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector",

abstract = "Measurements of the ZZ and WW final states in the mass range above the 2mZ and 2mW 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 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 ΓH/ΓSM 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.",

author = "\{ATLAS Collaboration\} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and R. Aben and M. Abolins and AbouZeid, \{O. S.\} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, \{B. S.\} and L. Adamczyk and Adams, \{D. L.\} and J. Adelman and S. Adomeit and T. Adye and Affolder, \{A. A.\} and T. Agatonovic-Jovin and Aguilar-Saavedra, \{J. A.\} and M. Agustoni and Ahlen, \{S. P.\} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, \{T. P.A.\} and G. Akimoto and Akimov, \{A. V.\} and Alberghi, \{G. L.\} and J. Albert and S. Albrand and \{Alconada Verzini\}, \{M. J.\} and M. Aleksa and Aleksandrov, \{I. N.\} and C. Alexa and G. Alexander and T. Alexopoulos and M. Alhroob and G. Alimonti and L. Alio and J. Alison and Alkire, \{S. P.\} and Allbrooke, \{B. M.M.\} and H. Arnold and \{Da Via\}, Cinzia and V. Dao and J. Hobbs and J. Jia and G. Piacquadio and D. Tsybychev",

note = "Publisher Copyright: {\textcopyright} CERN for the benefit of the ATLAS collaboration 2015.",

year = "2015",

doi = "10.1140/epjc/s10052-015-3542-2",

language = "English",

volume = "75",

pages = "1--34",

journal = "European Physical Journal C",

issn = "1434-6044",

number = "7",

}

TY - JOUR

T1 - Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector

AU - ATLAS Collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abdallah, J.

AU - Abdinov, O.

AU - Aben, R.

AU - Abolins, M.

AU - AbouZeid, O. S.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Abreu, R.

AU - Abulaiti, Y.

AU - Acharya, B. S.

AU - Adamczyk, L.

AU - Adams, D. L.

AU - Adelman, J.

AU - Adomeit, S.

AU - Adye, T.

AU - Affolder, A. A.

AU - Agatonovic-Jovin, T.

AU - Aguilar-Saavedra, J. A.

AU - Agustoni, M.

AU - Ahlen, S. P.

AU - Ahmadov, F.

AU - Aielli, G.

AU - Akerstedt, H.

AU - Åkesson, T. P.A.

AU - Akimoto, G.

AU - Akimov, A. V.

AU - Alberghi, G. L.

AU - Albert, J.

AU - Albrand, S.

AU - Alconada Verzini, M. J.

AU - Aleksa, M.

AU - Aleksandrov, I. N.

AU - Alexa, C.

AU - Alexander, G.

AU - Alexopoulos, T.

AU - Alhroob, M.

AU - Alimonti, G.

AU - Alio, L.

AU - Alison, J.

AU - Alkire, S. P.

AU - Allbrooke, B. M.M.

AU - Arnold, H.

AU - Da Via, Cinzia

AU - Dao, V.

AU - Hobbs, J.

AU - Jia, J.

AU - Piacquadio, G.

AU - Tsybychev, D.

PY - 2015

Y1 - 2015

N2 - Measurements of the ZZ and WW final states in the mass range above the 2mZ and 2mW 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 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 ΓH/ΓSM 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.

AB - Measurements of the ZZ and WW final states in the mass range above the 2mZ and 2mW 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 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 ΓH/ΓSM 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.

UR - https://www.scopus.com/pages/publications/84938379540

U2 - 10.1140/epjc/s10052-015-3542-2

DO - 10.1140/epjc/s10052-015-3542-2

M3 - Article

AN - SCOPUS:84938379540

SN - 1434-6044

VL - 75

SP - 1

EP - 34

JO - European Physical Journal C

JF - European Physical Journal C

IS - 7

M1 - 335

ER -

Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector

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