We study theoretical uncertainties in predicting top-quark pair-production near threshold at the LHC using the non-relativistic QCD framework. We include variations in the top-quark mass and width, the strong coupling αs, renormalization and factorization scales, and parton distribution functions, as well as uncertainties from the color-singlet and octet Green's functions that describe quasi-bound toponium formation. These uncertainties are compared with those from standard fixed-order QCD predictions, and implications for ATLAS and CMS analyses are discussed. For the LHC at 13 TeV center-of-mass energy, the integral of the top-quark pair invariant-mass distribution from 340 to 350 GeV is 11.67 pb with −1.47+1.43 pb uncertainty. The corresponding excess after subtracting the POWHEG-BOX result is 4.15 pb with the same uncertainties.
@article{arxiv.2604.09485,
title = {Threshold Top-Quark Pair-Production: Cross Sections and Key Uncertainties},
author = {Maria Vittoria Garzelli and Giovanni Limatola and Sven-Olaf Moch and Matthias Steinhauser and Oleksandr Zenaiev},
journal= {arXiv preprint arXiv:2604.09485},
year = {2026}
}