Speakers
Jean-Philippe Lansberg
(IPN Orsay, Paris Saclay U. / IN2P3-CNRS)
Jean-Philippe Lansberg
(Ecole Polytechnique)
Jean-Philippe Lansberg
(Ecole polytechnique)
Jean-Philippe Lansberg
(Université Paris-Saclay (FR))
Description
We address the issue of negative total cross sections for inclusive hadroproduction of pseudoscalar quarkonia ($\eta_Q$) and photoproduction of vector quarkonia ($\psi$, $\Upsilon$) at increasing energies in NLO collinear-factorisation computations in the $\overline{MS}$ scheme. We discuss two solutions:
- fixing the factorisation scale to avoid an over-subtraction of the collinear contributions by the Altarelli-Parisi counter terms at large partonic energies;
- resumming $\ln(1/z)$ contributions through high-energy factorisation with a new matching to collinear factorisation at finite $z$.
In both cases, we discuss the corresponding phenomenology at different energies including a detailed assessment of the theoretical uncertainties.
References:
- J.P. Lansberg, M. Nefedov and M.A. Ozcelik, Matching next-to-leading-order and high-energy-resummed calculations of heavy-quarkonium-hadroproduction cross sections, JHEP 05 (2022), 083
- A. Colpani Serri, Y. Feng, C. Flore, J.P. Lansberg, M.A. Ozcelik, H.S. Shao and Y. Yedelkina, Revisiting NLO QCD corrections to total inclusive $J/\psi$ and $\Upsilon$ photoproduction cross sections in lepton-proton collisions, [arXiv:2112.05060 [hep-ph]].
- J.P. Lansberg and M.A. Ozcelik, Curing the unphysical behaviour of NLO quarkonium production at the LHC and its relevance to constrain the gluon PDF at low scales, Eur. Phys. J. C 81 (2021) no.6, 497
[arXiv:2012.00702 [hep-ph]].
