We introduce a technique for the next-to-leading order accurate simulation of e+e−→W+W−bbˉ that respects the resonant nature of the process above and near the top-quark pair production threshold. The parton-shower evolution, infrared subtraction and NLO matching account in particular for finite width effects beyond the Breit-Wigner structure considered in resonance-aware approaches. We present first phenomenological results relevant to a potential future electron-positron collider and provide a publicly available simulator based on the ALARIC parton shower and the SHERPA event generator.
@article{arxiv.2604.13978,
title = {Resonance- and Width-aware Parton Shower Evolution and NLO Matching},
author = {Stefan Höche and Daniel Reichelt},
journal= {arXiv preprint arXiv:2604.13978},
year = {2026}
}