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Title: Measurement of the ZZ production cross section and Z → ℓ +ℓ' +ℓ' branching fraction in pp collisions at s = 13   TeV

Four-lepton production in proton–proton collisions, pp→(Z/γ*)(Z/γ*)→ℓ +ℓ' +ℓ' ,where ℓ,ℓ'=e or μ, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6 fb –1. The ZZ production cross section, σ(pp → ZZ)=14.6 –1.8 +1.9(stat) –0.3 +0.5(syst)±0.2(theo)±0.4(lumi)pb, is measured for events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60ℓ +,mℓ' +ℓ' <120 GeV60+ℓ ,mℓ' +ℓ' <120 GeV. The Z boson branching fraction to four leptons is measured to be B(Z→ℓ +ℓ' +ℓ' )=4.9 –0.7 +0.8 (stat) –0.2 +0.3 (syst)–0.1+0.2(theo)±0.1(lumi)×10 –6 for the four-lepton invariant mass in the range 80+ℓ ℓ' +ℓ' <100 GeV80+ℓ ℓ' +ℓ' <100 GeV and dilepton mass m + >4 GeV for all opposite-sign, same-flavor lepton pairs. Lastly, the results are in agreement with standard model predictions.
Authors:
 [1]
  1. Yerevan Physics Inst. (YerPhI) (Armenia). et al.
Publication Date:
OSTI Identifier:
1330899
Report Number(s):
FERMILAB-PUB-16-306-CMS; CMS-SMP-16-001; CERN-EP-2016-174; arXiv:1607.08834
Journal ID: ISSN 0370-2693; 1478600
Grant/Contract Number:
AC02-07CH11359
Type:
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 763; Journal Issue: C; Journal ID: ISSN 0370-2693
Publisher:
Elsevier
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
CMS
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS