Measurements of normalized differential cross sections of top quark pair (t¯t) production are presented as a function of the mass, the transverse momentum and the rapidity of the t¯t system in proton-proton collisions at center-of-mass energies of √s=7 and 8 TeV. The data set corresponds to an integrated luminosity of 4.6 fb−1 at 7 TeV and 20.2 fb−1 at 8 TeV, recorded with the ATLAS detector at the Large Hadron Collider. Events with top quark pair signatures are selected in the dilepton final state, requiring exactly two charged leptons and at least two jets with at least one of the jets identified as likely to contain a b hadron. The measured distributions are corrected for detector effects and selection efficiency to cross sections at the parton level. The differential cross sections are compared with different Monte Carlo generators and theoretical calculations of t¯t production. The results are consistent with the majority of predictions in a wide kinematic range.4 MoreReceived 26 July 2016Corrected 21 May 2020DOI:https://doi.org/10.1103/PhysRevD.94.092003Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.© 2016 CERN, for the ATLAS CollaborationPhysics Subject Headings (PhySH)Physical SystemsTop quarkParticles & Fields