Measurement of the differential cross section for top-quark-pair production in the dilepton channel at $\sqrt{s}$ = 13 TeV with the CMS detector

Abstract: Measurements of normalized differential top-quark-pair ($t\bar{t}$) production cross sections are performed using final states with two leptons ($e^+e^-$, $\mu^+\mu^-$, and $e^\pm\mu^\mp$) in proton-proton ($pp$) collisions at $\sqrt{s}$ = 13 TeV at the CERN LHC. The data were recorded in 2015 with the CMS detector and correspond to an integrated luminosity of 2.2 fb$^{-1}$. The $t\bar{t}$ production cross section is measured as a function of kinematic properties of the top quarks and the $t\bar{t}$ system in the full phase space, as well as of the jet multiplicity in the event in the fiducial phase space. Several perturbative quantum chromodynamics (QCD) calculations are confronted with the data and are found to be broadly in agreement with the measured results.