Measurement of vector boson production cross sections and their ratios using $pp$ collisions at $\sqrt{s}=13.6$ TeV with the ATLAS detector

Fiducial and total $W^{\pm }$ and $Z$ boson cross sections, their ratios and the ratio of top-antitop-quark pair and $W$-boson fiducial cross sections are measured in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13.6$ TeV, corresponding to an integrated luminosity of 29 fb${}^{-1}$ of data collected in 2022 by the ATLAS experiment at the Large Hadron Collider. The measured fiducial cross-section values for $W^{+}\to {\mathrm{\ell }}^{+}\nu$, $W^{-}\to {\mathrm{\ell }}^{-}\bar{\nu }$, and $Z\to {\mathrm{\ell }}^{+}{\mathrm{\ell }}^{-}$ ($\mathrm{\ell }=e$ or $\mu$) boson productions are $4250\pm 150$ pb, $3310\pm 120$ pb, and $744\pm 20$ pb, respectively, where the uncertainty is the total uncertainty, including that arising from the luminosity of about 2.2%. The measurements are in agreement with Standard-Model predictions calculated at next-to-next-to-leading-order in ${\alpha }_s$, next-to-next-to-leading logarithmic accuracy and next-to-leading-order electroweak accuracy.