First measurement of the top quark pair production cross section in proton-proton collisions at $\sqrt{s}=13.6\,\mathrm{TeV}$

The first measurement of the top quark pair ($\mathrm{t\bar{t}}$) production cross section in proton-proton collisions at $\sqrt{s}=13.6\,\mathrm{TeV}$ is presented. Data recorded with the CMS detector at the CERN LHC in July and August 2022 corresponding to an integrated luminosity of $1.20\pm0.07\,\mathrm{fb}^{-1}$ are analyzed. Events are selected with one or two charged leptons (electrons and muons) and additional jets. A maximum likelihood fit is performed to event categories defined by the number and flavors of the leptons, and the number of jets and jets identified as originating from the decay of b hadrons. An inclusive $\mathrm{t\bar{t}}$ production cross section of $887\,^{+43}_{-41}\,(\mathrm{stat+syst})\pm53\,(\mathrm{lumi})\,\mathrm{pb}$ is measured, in agreement with the standard model prediction of $921\,^{+29}_{-37}\,\mathrm{pb}$.