Boosted Top Quarks in the Peak Region with N$^3$LL Resummation

TL;DR

This paper presents a high-precision theoretical calculation of boosted top quark pair production in electron-positron collisions, achieving improved mass determination accuracy through advanced resummation and renormalon subtraction techniques.

Contribution

It introduces N$^3$LL resummation combined with NNLO fixed-order corrections within effective field theories, enhancing the precision of top quark mass extraction from collider data.

Findings

Perturbative uncertainties are reduced below 100 MeV for the top MSR mass.

Partial cancellation observed between pole mass and soft function renormalons.

Improved stability of the peak position in the 2-jettiness distribution.

Abstract

We present results for the 2-jettiness differential distribution for boosted top quark pairs produced in $e^+e^-$ collisions in the peak region accounting for QCD large-logarithm resummation at next-to-next-to-next-to-leading logarithmic (N$^3$LL) order and fixed-order corrections to matrix elements at next-to-next-to-leading order (NNLO) calculated in the framework of soft-collinear effective theory and boosted heavy quark effective theory. Electroweak and finite-width effects are included at leading order. We study the perturbative convergence of the cross section in the pole and MSR mass schemes, with and without soft gap subtractions. We find that there is a partial cancellation between the pole mass and soft function renormalons. When renormalon subtractions concerning the top mass and the soft function are implemented, the perturbative uncertainties are, however, systematically smaller and an improvement in the stability of the peak position is observed. We find that the top MSR mass may be determined with perturbative uncertainties well below $100$\,MeV from the peak position of the 2-jettiness distribution. This result has important applications for Monte Carlo top quark mass calibrations.