Production of heavy quarkonia (charmonia and bottomonia), both inclusively (in e^+e^-, ep and pp collisions) and exclusively (e.g. exclusive photoproduction) stays a very active area of theoretical and experimental research, because several phenomenological puzzles are still open and awaiting resolution. In the talk, results obtained in the new approach [1,2,3] to the application of High-Energy Factorisation to the heavy-quarkonium production physics, based on matching with collinear factorisation will be reviewed. New results on the application of the approach to exclusive J/psi and Upsilon photoproduction will be presented. The progress [3] in going beyond the Doubly-Logarithmic Approximation of Refs.[1,2] will be discussed.
[1] 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, 083 (2022)
doi:10.1007/JHEP05(2022)083
[arXiv:2112.06789 [hep-ph]].
[2] J.P. Lansberg, M. Nefedov and M.A. Ozcelik,
``Curing the high-energy perturbative instability of vector-quarkonium-photoproduction cross sections at order alpha*alpha _s^3 with high-energy factorisation,''
Eur. Phys. J. C 84, no.4, 351 (2024)
doi:10.1140/epjc/s10052-024-12588-x
[arXiv:2306.02425 [hep-ph]].
[3] M. Nefedov,
``On the high-energy instability of quarkonium production,''
Nucl. Part. Phys. Proc. 343, 11-16 (2024)
doi:10.1016/j.nuclphysbps.2023.11.012
[arXiv:2309.09608 [hep-ph]].