Measurement of the differential cross section for $\mathrm{t \bar t}$ production in the dilepton final state at $\sqrt{s}=13~\mathrm{TeV}$

Measurements of normalized differential top quark pair ($\mathrm{t \bar t}$) production cross sections in proton-proton collisions at a centre-of-mass energy of 13 TeV at the CERN LHC are presented. The data were recorded in 2015 with the CMS detector and correspond to an integrated luminosity of $2.2~\mathrm{fb^{-1}}$. The measurements are performed in the dilepton decay channels ($\mathrm{e^+e^-}$, $\mu^+\mu^-$, and $\mu^{\pm} \mathrm{e^{\mp}}$). The $\mathrm{t \bar t}$ production cross section is measured as a function of kinematics of the top quarks, the $\mathrm{t \bar t}$ system, and of the number of jets in the event. The results are compared with several perturbative QCD calculations and are found to be broadly in agreement with the predictions.