Top Quark Mass Calibration for Monte Carlo Event Generators

The most precise top quark mass measurements use kinematic reconstruction methods, determining the top mass parameter of a Monte Carlo event generator m$MC\atop{t}$. Because of hadronization and parton-shower dynamics, relating m$MC\atop{t}$ to a field theory mass is difficult. Here, we present a calibration procedure to determine this relation using hadron level QCD predictions for observables with kinematic mass sensitivity. Fitting e+e-2-jettiness calculations at next-to-leading-logarithmic and next-to-next-to-leading-logarithmic order to PYTHIA 8.205, m$MC\atop{t}$ differs from the pole mass by 900 and 600 MeV, respectively, and agrees with the MSR mass within uncertainties, m$MC\atop{t}$ ≃ m$MSR\atop{t,1 GeV}$.