Measurements of Higgs boson production and couplings in the four-lepton channel in p p collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector
The final ATLAS Run 1 measurements of Higgs boson production and couplings in the decay channel H →Z Z*→ℓ+ℓ-ℓ'+ℓ'- , where ℓ , ℓ'=e or μ , are presented. These measurements were performed using p p collision data corresponding to integrated luminosities of 4.5 and 20.3 fb-1 at center-of-mass energies of 7 and 8 TeV, respectively, recorded with the ATLAS detector at the LHC. The H →Z Z*→4 ℓ signal is observed with a significance of 8.1 standard deviations, with an expectation of 6.2 standard deviations, at mH =125.36 GeV , the combined ATLAS measurement of the Higgs boson mass from the H →γ γ and H →Z Z*→4 ℓ channels. The production rate relative to the Standard Model expectation, the signal strength, is measured in four different production categories in the H →Z Z*→4 ℓ channel. The measured signal strength, at this mass, and with all categories combined, is 1.44-0.33+0.40 . The signal strength for Higgs boson production in gluon fusion or in association with t t ̄ or b b ̄ pairs is found to be 1.7-0.4+0.5 , while the signal strength for vector-boson fusion combined with W H /Z H associated production is found to be 0.3-0.9+1.6 .
Physical Review D
- Pub Date:
- January 2015
- Standard-model Higgs bosons;
- High Energy Physics - Experiment
- 40 pages plus author list + cover pages (54 pages total), 21 figures, 12 tables, submitted to Physical Review D, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2013-21/