Measurements of $\text{t}\bar{\text{t}}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in pp collisions at $\sqrt{s} = 13\ \text{TeV}$ using the ATLAS detector

Measurements are presented of the highly boosted top-quark pair production differential cross-section in 13 TeV pp collisions in the all-hadronic decay mode, using 36.1 fb$^{-1}$ of data collected by the ATLAS detector in 2015 and 2016. The tt ̄ process is measured by requiring two top-quark candidates, one with pT > 500 GeV and a second with pT > 350 GeV, with each candidate reconstructed as anti-kt jets with radius parameter R = 1.0. The top-quark candidates are separated from the multijet background using the jet substructure and the presence of a b-quark tag in each jet. The observed kinematic distributions are unfolded to recover the differential cross-sections in a fiducial phase-space region at the particle-level. The observed distributions are also unfolded to obtain the differential cross-sections at the parton-level for a similar phase-space region. The particle-level and parton-level unfolded differential cross-sections are compared with several Standard Model Monte Carlo predictions.