Measurement of the top-quark mass in $t\bar{t}+1$-jet events collected with the ATLAS detector in $pp$ collisions at $\sqrt{s}=8$ TeV

Understand

A determination of the top-quark mass is presented using 20.2 $\text{fb}^{-1}$ of 8 TeV proton-proton collision data produced by the Large Hadron Collider and collected by the ATLAS experiment.

• The normalised differential cross section of top-quark pair production in association with an energetic jet is measured in the lepton+jets final state and unfolded to parton and particle levels.
• The unfolded distribution at parton level can be described using next-to-leading-order QCD predictions in terms of either the top-quark pole mass or the running mass as defined in the (modified) minimal subtraction scheme.
• A comparison between the experimental distribution and the theoretical prediction allows the top-quark mass to be extracted in the two schemes.