Measurements of four-lepton production in $pp$ collisions at $\sqrt s =$ 8 TeV with the ATLAS detector

A measurement of four-lepton ($4\ell$) production in proton-proton collisions at 8 TeV with the ATLAS experiment at the Large Hadron Collider (LHC), is presented. The analysis considers $4\ell$ production modes in the invariant mass range between 80~GeV and 1~TeV. Fiducial and total cross sections measurements are presented separately for the investigated $4\ell$ topologies as well as for their combination. The combined $4\ell$ fiducial cross section is also measured as a function of the four-lepton invariant mass, $m(4\ell)$, and transverse momentum, $p_{\mathrm{T}}^{4\ell}$. The signal-strenght of $4\ell$ production induced by gluon-fusion for $m(4\ell)\geq 180$ GeV is presented. The data are found to agree with the theoretical predictions confirming the validity of the Standard Model and its scalar sector in a wide kinematic regime.