Measurement of the inclusive $\mathrm{t}\bar{\mathrm{t}}$ production cross section in pp collisions at $\sqrt{s} = 5.02\,\mathrm{TeV}$

The top quark pair production cross section is measured in proton-proton collisions at a center-of-mass energy of $5.02\,\mathrm{TeV}$. The data collected in 2017 by the CMS experiment at the LHC corresponding to an integrated luminosity of $304\,\mathrm{pb}^{-1}$ are analyzed. The measurement is performed using events with one electron and one muon of opposite sign, and at least two jets. The measured cross section is found to be $60.3~\pm~5.0~\text{(stat)}~\pm~2.8~\text{(syst)}~\pm 0.9~\text{(lum)}~{\mathrm{pb}}$. To reduce the statistical uncertainty, a combination with the result in the $\ell+$jets channel, based on $27.4\,\mathrm{pb}^{-1}$ of data collected in 2015 at the same center-of-mass energy of $5.02\,\mathrm{TeV}$, is then performed, obtaining a value of $62.6~\pm~4.1~\text{(stat)}~\pm~3.0~{(\text{syst+lumi})}~{\mathrm{pb}}$, with a total uncertainty of $7.9\%$, in agreement with the standard model.