Measurement of $ZZ$ production cross-sections in the four-lepton final state in $pp$ collisions at $\sqrt{s}=13.6$ TeV with the ATLAS experiment

This paper reports cross-section measurements of $ZZ$ production in $pp$ collisions at $\sqrt{s}=13.6$ TeV at the Large Hadron Collider. The data were collected by the ATLAS detector in 2022, and correspond to an integrated luminosity of 29 fb${}^{-}1$. Events in the $ZZ\to 4\mathrm{\ell }$ ($\mathrm{\ell }=e$, $\mu$) final states are selected and used to measure the inclusive and differential cross-sections in a fiducial region defined close to the analysis selections. The inclusive cross-section is further extrapolated to the total phase space with a requirement of 66 $<m_Z<$ 116 GeV for both $Z$ bosons, yielding $16.8\pm 1.1$ pb. The results are well described by the Standard Model predictions.