Measurements of Higgs boson production and couplings in the four-lepton channel in pp collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector

• Main Author: Taylor, Frank E. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2015-03-11T15:23:01Z.
• Subjects: Article
• Online Access: Get fulltext

The final ATLAS Run 1 measurements of Higgs boson production and couplings in the decay channel H→ZZ*→ℓ[superscript +]ℓ[superscript−]ℓ' [superscript +], ℓ' [superscript −], where ℓ, ℓ'=e or μ, are presented. These measurements were performed using pp collision data corresponding to integrated luminosities of 4.5 and 20.3  fb[superscript −1] at center-of-mass energies of 7 and 8 TeV, respectively, recorded with the ATLAS detector at the LHC. The H→ZZ*→4ℓ 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→γγ and H→ZZ*→4ℓ channels. The production rate relative to the Standard Model expectation, the signal strength, is measured in four different production categories in the H→ZZ*→4ℓ channel. The measured signal strength, at this mass, and with all categories combined, is 1.44[superscript +0.40 subscript −0.33]. The signal strength for Higgs boson production in gluon fusion or in association with tt¯ or bb¯ pairs is found to be 1.7[superscript +0.5 subscript −0.4], while the signal strength for vector-boson fusion combined with [WH over ZH] associated production is found to be 0.3[superscript +1.6 subscript −0.9].
United States. Dept. of Energy
National Science Foundation (U.S.)
Brookhaven National Laboratory