2008/01/31 by CDF Collaboration, J. Adelman, T. Aaltonen +98 · 4 citations
Mathematics · Physics and Astronomy · #Algorithm #Astrophysics #Boson #Collider Detector at Fermilab #High-Energy Particle Collisions Research #Large Hadron Collider #Luminosity #Mathematics #Order (exchange) #Particle physics #Particle physics theoretical and experimental studies #Physics #Production (economics) #Quantum Chromodynamics and Particle Interactions #Standard Model (mathematical formulation) #hep-ex
paper · pdf · doi:10.1103/physrevlett.100.201801
published as Phys.Rev.Lett.100:201801,2008 · 7 pages, 1 figure. Submitted to Phys. Rev. Lett
arxiv created 2008/01/31 · openalex publication_date 2008/05/22 · arxiv updated 2010/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report the first evidence of Z boson pair production at a hadron collider with a significance exceeding 4 standard deviations. This result is based on a data sample corresponding to 1.9 fb^\ensuremath-1 of integrated luminosity from pp collisions at √(s)=1.96 TeV collected with the Collider Detector at Fermilab II detector. In the \ensuremathℓ\ensuremathℓ\ensuremathℓ^\ensuremath'\ensuremathℓ^\ensuremath' channel, we observe three ZZ candidates with an expected background of 0.096_\ensuremath-0.063+0.092 events. In the \ensuremathℓ\ensuremathℓ\ensuremathν\ensuremathν channel, we use a leading-order calculation of the relative ZZ and WW event probabilities to discriminate between signal and background. In the combination of \ensuremathℓ\ensuremathℓ\ensuremathℓ^\ensuremath'\ensuremathℓ^\ensuremath' and \ensuremathℓ\ensuremathℓ\ensuremathν\ensuremathν channels, we observe an excess of events with a probability of 5.1\ifmmode×\else\texttimes\fi10^\ensuremath-6 to be due to the expected background. This corresponds to a significance of 4.4 standard deviations. The measured cross section is \ensuremathσ(pp\ensuremath→ZZ)=1.4_\ensuremath-0.6+0.7(stat+syst) pb, consistent with the standard model expectation.