Differential cross-section measurements of top-quark-pair production in the dilepton final state at 13 TeV with the ATLAS experiment

Measurements of top-quark pair differential cross-sections are a test of the Standard Model and quantum chromodynamics, and can be sensitive to possible new physics. They also provide inputs for modelling top-quark kinematics in simulations. Differential cross-sections are measured as a function of the transverse momentum and absolute rapidity of the top quark, and of the transverse momentum, absolute rapidity and invariant mass of the $t\bar{t}$ system, using an integrated luminosity of 3.2 fb$^{-1}$ of proton-proton data at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV recorded by the ATLAS experiment at the LHC in 2015. The $t\bar{t}$ events are selected by requiring one electron and one muon of opposite electric charge, and at least two jets, one of which must be tagged as containing a $B$-hadron. The measured differential cross-sections are compared to predictions of NLO generators matched to parton showers.