Precision determination of the top-quark mass

Precision determinations of the top-quark mass require theory predictions with a well-defined mass parameter in a given renormalization scheme. The top-quark's running mass in the MSbar scheme can be extracted with good precision from the total cross section at next-to-next-to-leading order in QCD. The Monte Carlo top-quark mass parameter measured from comparison to events with top-quark decay products is not identical with the pole mass. Its translation to the pole mass scheme introduces an additional uncertainty of the order of 1 GeV.