2026-04-17T07:39:22Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/2218472025-12-05T16:56:45Zcom_2072_1057col_2072_478823col_2072_478917

00925njm 22002777a 4500 dc Comerma Montells, Albert author Garcia Moreno, Paula author Garrido Beltrán, Lluís author Gioventù, Alessandra author Gironella Gironell, Pere author Gomez Fernandez, Sergio author Graugés Pous, Eugeni author Lobo Salvia, Aniol author López Huertas, Albert author Manera Escalero, Rafel author Marin Benito, Carla author Mauricio Ferre, Joan author Alfonso Albero, Alejandro author Vazquez Gomez, Ricardo author LHCb Collaboration author 2025-06-27T13:39:40Z 2025-06-27T13:39:40Z 2024 2025-06-27T13:39:40Z The ratio of production cross-sections of ψ(2S) over J/ψ mesons as a function of charged-particle multiplicity in proton-proton collisions at a centre-of-mass energy √ s = 13 TeV is measured with a data sample collected by the LHCb detector, corresponding to an integrated luminosity of 658 pb−1 . The ratio is measured for both prompt and non-prompt ψ(2S) and J/ψ mesons. When there is an overlap between the rapidity ranges over which multiplicity and charmonia production are measured, a multiplicity-dependent modifcation of the ratio is observed for prompt mesons. No signifcant multiplicity dependence is found when the ranges do not overlap. For non-prompt production, the ψ(2S)-to-J/ψ production ratio is roughly independent of multiplicity, irrespective of the rapidity range over which the multiplicity is measured. The results are compared to predictions of the co-mover model and agree well except in the low multiplicity region. The ratio of production cross-sections of ψ(2S) over J/ψ mesons are cross-checked with other measurements in di-lepton channels and found to be compatible.  Col·lisions d'ions pesats Hadrons Física de partícules Heavy ion collision Hadrons Particle physics Multiplicity dependence of σψ(2S)/σJ/ψ in pp collisions at √s = 13 TeV