UNSPECIFIED (2015) Measurements of four-lepton production in pp collisions at √s = 8 TeV source with the ATLAS detector. Physics Letters B, 753. pp. 552-572. ISSN 0370-2693
1_s2.0_S037026931500996X_main.pdf - Published Version
Available under License Creative Commons Attribution.
Download (1MB)
Abstract
The four-lepton (4ℓ , ℓ=e,μ) production cross section is measured in the mass range from 80 to 1000 GeV using 20.3 fb−1 of data in pp collisions at √s = 8 TeV collected with the ATLAS detector at the LHC. The 4ℓ events are produced in the decays of resonant Zand Higgs bosons and the non-resonant ZZ continuum originating from qq¯, gg, and qg initial states. A total of 476 signal candidate events are observed with a background expectation of 26.2±3.6 events, enabling the measurement of the integrated cross section and the differential cross section as a function of the invariant mass and transverse momentum of the four-lepton system. In the mass range above 180 GeV, assuming the theoretical constraint on the production cross section calculated with perturbative NNLO QCD and NLO electroweak corrections, the signal strength of the gluon-fusion component relative to its leading-order prediction is determined to be μgg=2.4±1.0 (stat.)±0.5 (syst.)±0.8 (theory).