Top Quark Mass Calibration for Monte Carlo Event Generators

Abstract

The most precise top quark mass measurements use kinematic reconstruction methods, determining the top mass parameter of a Monte Carlo event generator, $m_t^{\mathrm{MC}}$. Due to hadronization and parton shower dynamics, relating $m_t^{\mathrm{MC}}$ to a field theory mass is difficult. 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 NLL/NNLL order to Pythia 8.205, $m_t^{\mathrm{MC}}$ differs from the pole mass by $900$/$600$ MeV, and agrees with the MSR mass within uncertainties, $m_t^{\mathrm{MC}}\simeq m_{t,1\mathrm{GeV}}^{\mathrm{MSR}}$.

Comments: 6 pages, 3 figures