We present NNLO QCD predictions for a wide range of event-shape observables in hadronic Higgs decays, taking into account the two dominant decay modes H→gg and H→bbˉ. Specifically, we consider the six classical event shapes thrust, heavy jet mass, C-parameter, total and wide jet broadening, and the three-jet resolution y23 in the Durham algorithm. We also present results for the soft-drop variant of thrust. Decays of the Higgs boson to two gluons are treated in the heavy-top limit, whereas decays to a bottom-quark pair are mediated by a non-vanishing Yukawa coupling, despite considering kinematically massless quarks. Our results highlight the importance of NNLO QCD corrections in the calculation of event-shape observables and provide means to quantify the intrinsic difference between the two Higgs decay modes.
@article{arxiv.2508.14282,
title = {Precise Predictions for Event Shapes in Hadronic Higgs Decays},
author = {Elliot Fox and Aude Gehrmann-De Ridder and Thomas Gehrmann and Nigel Glover and Matteo Marcoli and Christian T. Preuss},
journal= {arXiv preprint arXiv:2508.14282},
year = {2025}
}