@inproceedings{1a031593-9824-4ba9-92f5-6129c0d17b59,
  abstract     = {{<p>The observation of an excess of tt production in the threshold region, by CMS and ATLAS, has been interpreted as a toponium contribution, i.e. from below-threshold tt virtual states. The news here is the nontrivial experimental extraction of such a signal, not its existence as such. Indeed, already 35+ years ago an NRQCD Green’s function approach was used to model the above- and below-threshold production of tt pairs in pp/pp collisions. The relevant cross section equations from that study are now (re-)implemented in the Pythia 8 event generator. While the above-threshold part is straightforward, the physical interpretation and modelling of below-threshold events is nontrivial, and a final prescription is cross-checked against two simpler ones. Cross sections and some event properties are presented.</p>}},
  author       = {{Sjöstrand, Torbjörn}},
  booktitle    = {{Proceedings of Science}},
  language     = {{eng}},
  title        = {{On the threshold behaviour of heavy top production}},
  url          = {{http://dx.doi.org/10.22323/1.508.0002}},
  doi          = {{10.22323/1.508.0002}},
  volume       = {{508}},
  year         = {{2026}},
}