First measurement of the top quark pair production cross section at $\sqrt{s}=13.6\mathrm{T}\mathrm{e}\mathrm{V}$ at the CMS experiment

We present the first measurement of the top quark pair production cross section at the new LHC center-of-mass energy of $\sqrt{s}=13.6\mathrm{T}\mathrm{e}\mathrm{V}$, using $1.20{\mathrm{f}\mathrm{b}}^{-1}$ of data recorded at the CMS detector. We use a new method combining dilepton and lepton+jets decay channels, constraining several experimental uncertainties in situ. A cross section of $887_{-41}^{+43}(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}+\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\pm 53(\mathrm{l}\mathrm{u}\mathrm{m}\mathrm{i})\mathrm{p}\mathrm{b}$ is measured, in agreement with the standard model. This result constitutes a first validation of the new data taken by CMS in LHC Run 3.