Abstract
An error was found in the published version in the top plot in Fig. 1. The plot was erroneously replaced by a copy of the top plot of Fig. 4. The correct figure is shown below. The physics conclusions of the paper remain unchanged.
Four-lepton production in proton–proton collisions, $pp→(Z/γ⁎)(Z/γ⁎)→ℓ^+ℓ^−ℓ'^+ℓ'^−$, 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, $σ(pp→ZZ)=14.6^{+1.9}_{-1.8}(stat)^{+0.5}_{−0.3}(syst)±0.2(theo)±0.4(lumi)pb$, is measured for events with two opposite-sign, same-flavor lepton pairs produced in the mass region $60<m_{ℓ^+ℓ^−},m_{ℓ'^+ℓ'^−}<120GeV$. The Z boson branching fraction to four leptons is measured to be $\mathcal{B}(Z→ℓ^+ℓ^−ℓ'^+ℓ'^−)=4.9^{+0.8}_{−0.7} (stat)^{+0.3}_{−0.2} (syst)+0.2−0.1(theo)±0.1(lumi)×10^{−6}$ for the four-lepton invariant mass in the range $80<m_{ℓ^+ℓ^−ℓ'^+ℓ'^−}<100GeV$ and dilepton mass $m_{ℓ^+ℓ^-}>4GeV$ for all opposite-sign, same-flavor lepton pairs. The results are in agreement with standard model predictions.