Aaij, R.Alfonso Albero, AlejandroGarcia Moreno, PaulaGarrido Beltrán, LluísGironella Gironell, PereGomez Fernandez, S.Graugés Pous, EugeniLobo Salvia, AniolMarin Benito, CarlaMauricio, J.Vazquez Gomez, RicardoLHCb collaboration2025-04-252025-04-2520231126-6708https://hdl.handle.net/2445/220635The cross-sections of exclusive (coherent) photoproduction J/ψ and ψ(2S) mesons in ultra-peripheral PbPb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV are measured using a data sample corresponding to an integrated luminosity of 228 ± 10 µb −1 , collected by the LHCb experiment in 2018. The differential cross-sections are measured separately as a function of transverse momentum and rapidity in the nucleus-nucleus centre-of-mass frame for J/ψ and ψ(2S) mesons. The integrated cross-sections are measured to be σ coh J/ψ = 5.965 ± 0.059 ± 0.232 ± 0.262 mb and σ coh ψ(2S) = 0.923 ± 0.086 ± 0.028 ± 0.040 mb, where the first listed uncertainty is statistical, the second systematic and the third due to the luminosity determination. The cross-section ratio is measured to be σ coh ψ(2S)/σcoh J/ψ = 0.155 ± 0.014 ± 0.003, where the first uncertainty is statistical and the second is systematic. These results are compatible with theoretical predictions.25 p.application/pdfengcc-by (c) Aaij, R. et al., 2023http://creativecommons.org/licenses/by/4.0/Col·lisions (Física nuclear)Física de partículesExperimentsCollisions (Nuclear physics)Particle physicsExperimentsinfo:eu-repo/semantics/article7577272025-04-25info:eu-repo/semantics/openAccess