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dc.contributor.authorChatrchyan, S.
dc.contributor.authorKhachatryan, Vardan
dc.contributor.authorSirunyan, A.M.
dc.contributor.authorTumasyan, A.R.
dc.contributor.authorAdam, Wolfgang
dc.contributor.authorBaarmand, Marc M.
dc.contributor.authorDorney, B.
dc.contributor.authorHohlmann, Marcus
dc.contributor.authorKalakhety, Himali
dc.contributor.authorVodopiyanov, Igor
dc.date.accessioned2016-09-14T13:42:20Z
dc.date.available2016-09-14T13:42:20Z
dc.date.issued2012-12-07
dc.identifier.citationThe CMS collaboration, Chatrchyan, S., Khachatryan, V. et al. J. High Energ. Phys. (2012) 2012: 34. doi:10.1007/JHEP12(2012)034en_US
dc.identifier.urihttp://hdl.handle.net/11141/1010
dc.description.abstractThe first observation of the Z boson decaying to four leptons in proton-proton collisions is presented. The analyzed data set corresponds to an integrated luminosity of 5.02 fb−1 at √s = 7 TeV collected by the CMS detector at the Large Hadron Collider. A pronounced resonance peak, with a statistical significance of 9.7 σ, is observed in the distribution of the invariant mass of four leptons (electrons and/or muons) with mass and width consistent with expectations for Z boson decays. The branching fraction and cross section reported here are defined by phase space restrictions on the leptons, namely, 80 < m4` < 100 GeV, where m4` is the invariant mass of the four leptons, and m`` > 4 GeV for all pairs of leptons, where m`` is the two-lepton invariant mass. The measured branching fraction is B(Z → 4`) = 4.2+0.9−0.8 (stat.) ± 0.2(syst.) ) × 10−6 and agrees with the standard model prediction of 4.45 × 10−6. The measured cross section times branching fraction is σ(pp → Z) B(Z → 4`) = 112+23 −20(stat.)+7−5 (syst.)+3−2 (lumi.) fb, also consistent with the standard model prediction of 120 fb. The four-lepton mass peak arising from Z → 4` decays provides a calibration channel for the Higgs boson search in the H → ZZ → 4` decay mode.en_US
dc.language.isoen_USen_US
dc.rightsThe Journal of High Energy Physics (JHEP) is an open-access journal funded by SCOAP3 (scoap3.org) and licensed under CC BY 4.0en_US
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en_US
dc.titleObservation of Z decays to four leptons with the CMS detector at the LHCen_US
dc.typeArticleen_US
dc.identifier.doi10.1007/JHEP12(2012)034


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The Journal of High Energy Physics (JHEP) is an open-access journal funded by SCOAP3 (scoap3.org) and licensed under CC BY 4.0
Except where otherwise noted, this item's license is described as The Journal of High Energy Physics (JHEP) is an open-access journal funded by SCOAP3 (scoap3.org) and licensed under CC BY 4.0