CMS_2012_I1298807

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A measurement of the inclusive $ZZ$ production cross section and constraints on anomalous triple gauge couplings in proton-proton collisions at $\sqrt{s} = 8 TeV$ are presented. The analysis is based on a data sample, corresponding to an integrated luminosity of 19.6/fb, collected with the CMS experiment at the LHC. The measurements are performed in the leptonic decay modes $ZZ \to lll^\prime l^\prime$, where $l = e,\mu$ and $l^\prime = e, \mu, \tau$. The measured total cross section $ \sigma (pp \to ZZ) = 7.7 \pm 0.5 (\mathrm{stat}) + 0.5 -0.4 (\mathrm{syst}) \pm 0.4 (\mathrm{theo}) \pm 0.2 (\mathrm{lumi}) pb$, for both $Z$ bosons produced in the mass range $60 < m_Z < 120 \text{GeV}$, is consistent with standard model predictions. Differential cross sections, in phase space $p_T(\mu) > 5 \text{GeV}$, $p_T(e) > 7 \text{GeV}$, $|\eta(\mu)|<2.4$ , $|\eta(e)|<2.5$ and the 60--120 \text{GeV} mass requirement, are measured and well described by the theoretical predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous $ZZZ$ and $ZZ\gamma$ couplings at the 95\% confidence level, $-0.004 < f4Z < 0.004$, $-0.004 < f5Z < 0.004$, $-0.005 < f4\gamma < 0.005$, and $-0.005 < f5\gamma < 0.005.$

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