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

	Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector
	ATLAS Collaboration
刊名	EUROPEAN PHYSICAL JOURNAL C
	2015
卷号	75 期号:7 页码:335
英文摘要	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 -> 2l2 nu and WW -> e nu mu nu 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 root 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 Gamma(H)/Gamma(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.
学科主题	Physics
类目[WOS]	Physics, Particles & Fields
收录类别	SCI
WOS记录号	WOS:000361908300011
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/228795]
专题	高能物理研究所_实验物理中心
推荐引用方式 GB/T 7714	ATLAS Collaboration. Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector[J]. EUROPEAN PHYSICAL JOURNAL C,2015,75(7):335.
APA	ATLAS Collaboration.(2015).Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector.EUROPEAN PHYSICAL JOURNAL C,75(7),335.
MLA	ATLAS Collaboration."Constraints on the off-shell Higgs boson signal strength in the high-mass ZZ and WW final states with the ATLAS detector".EUROPEAN PHYSICAL JOURNAL C 75.7(2015):335.