Measurement of differential cross-section of $t\bar{t}$ and $t\bar{t}+b\bar{b}$ production with the ATLAS detector.

Measurements of differential cross-sections of top-quark pairs production are presented as a function of bottom-quark and $t\bar{t}$ system kinematic observables in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13~$TeV. The measurements were performed for $t\bar{t}$ and $t\bar{t}+b\bar{b}$ processes using data collected with the ATLAS detector at the LHC, corresponding to integrated luminosities of 3.2 and 36.1$~fb^{-1}$ respectivelly. The data is unfolded to generator-level after background subtraction to correct for detector resolution and acceptance effects and compared to the predictions of several Monte Carlo generators. Comparisons show general good agreement between the unfolded data and the theoretical predictions. The main sources of uncertainties arise from jet energy scale and resolution, as well as b-tagging efficiency corrections and modeling of additional jets in parton shower.