Measurement of the tt̄ t t ¯ production cross section, the top quark mass, and the strong coupling constant using dilepton events in pp collisions at √s=13\,TeV s = 13 Te

A measurement of the top quark-antiquark pair production cross section tt in proton-proton collisions at a centre-of-mass energy of 13 TeV is presented. The data correspond to an integrated luminosity of 35.9 fb -1 , recorded by the CMS experiment at the CERN LHC in 2016. Dilepton events (e , + -, e + e -) are selected and the cross section is measured from a likelihood fit. For a top quark mass parameter in the simulation of m MC t = 172.5 GeV the fit yields a measured cross section tt = 803 2 (stat) 25 (syst) 20 (lumi) pb, in agreement with the expectation from the standard model calculation at next-to-next-toleading order. A simultaneous fit of the cross section and the top quark mass parameter in the powheg simulation is performed. The measured value of m MC t = 172.33 0.14 (stat) +0.66 -0.72 (syst) GeV is in good agreement with previous measurements. The resulting cross section is used, together with the theoretical prediction, to determine the top quark mass and to extract a value of the strong coupling constant with different sets of parton distribution functions.