Speaker
Description
see summary/abstract.
This talk is on behalf of the ATLAS Collaboration.
Summary
Measurements of the inclusive and differential top-quark
pair production cross sections in proton-proton collisions with the
ATLAS detector at the Large Hadron Collider are presented at a center
of mass energy of 8 TeV and 13 TeV. The inclusive measurements reach
high precision and are compared to the best available theoretical
calculations. Differential measurements of the kinematic properties of
top quark pair production are also discussed. These measurements,
including results using boosted tops, probe our understanding of top
pair production in the TeV regime. The results, unfolded to particle
and parton level, are compared to Monte Carlo generators implementing
LO and NLO matrix elements matched with parton showers and NLO QCD
calculations. The production of top-quark pairs in association with W
and Z bosons is also presented. The measurement uses events with
multiple leptons and in particular probes the coupling between the top
quark and the Z boson. The cross-section measurement of photons
produced in association with top-quark pairs is also discussed. The
production cross-section of top-quark pairs in association with
additional light or heavy jets is presented. These process are
important backgrounds to searches for new physics and are all compared
to the best available theoretical calculations.
