$ZZ\rightarrow\ell^{+}\ell^{-}\ell '^{+} \ell '^{-}$ cross-section measurements and aTGC search in 13 TeV $pp$ collisions with the ATLAS detector

Measurements of $ZZ$ production in the $\ell^{+}\ell^{-}\ell^{\prime +}\ell^{\prime -}$ channel in proton-proton collisions at 13 TeV center-of-mass energy at the Large Hadron Collider are presented, using 36.1 $\mathrm{fb}^{-1}$ of data collected by the ATLAS experiment in 2015 and 2016. Here $\ell$ and $\ell'$ stand for electrons or muons. Integrated and differential $ZZ \to \ell^{+}\ell^{-}\ell^{\prime +}\ell^{\prime -}$ cross sections with $Z \to \ell^+\ell^-$ candidate masses in the range of 66 GeV to 116 GeV are measured in a fiducial phase space corresponding to the detector acceptance and corrected for detector effects. The differential cross sections are presented in bins of twenty observables, including several that describe the jet activity. The integrated cross section is also extrapolated to a total phase space and to all Standard-Model decays of $Z$ bosons with mass between 66 GeV and 116 GeV, resulting in a value of $17.2 \pm 0.9$ [$\pm 0.6$ (stat.) $\pm 0.4$ (syst.) $\pm 0.6$ (lumi.)] pb. The measurements are found to be in good agreement with the Standard-Model predictions. Exclusion limits on anomalous neutral triple gauge coupling parameters are set.