The production ratio of ψ(2S) to J/ψ charmonium states is presented as a function of multiplicity in proton-lead collisions at a centre-of-mass energy of sNN=8.16 TeV, for both prompt and nonprompt sources. The total luminosity recorded by the LHCb experiment corresponds to 13.6 nb−1 for pPb collisions and 20.8 nb−1 for Pbp collisions, where the first particle corresponds to the particle traveling towards the detector. Measurements are performed in the dimuon final state at forward (backward) centre-of-mass rapidity, with respect to the proton direction, 1.5 < y*< 4.0 (−5.0 < y*< −2.5) for pPb (Pbp) collisions. A multiplicity dependence of the prompt production ratio is observed in pPb collisions, whereas no dependence is found in nonprompt production, nor in either prompt or nonprompt production in Pbp collisions. These results suggest that in the Pb-going direction additional suppression mechanisms beyond comover effects may be present, possibly related to the formation of quark-gluon plasma. This highlights a transition from small to large collision systems and provides important insight into the suppression of charmonia in proton-nucleus collisions.

Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2025). Measurement of ψ(2S) to J/ψ cross-section ratio as function of multiplicity in pPb collisions at sNN=8.16 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2025(11) [10.1007/JHEP11(2025)169].

Measurement of ψ(2S) to J/ψ cross-section ratio as function of multiplicity in pPb collisions at sNN=8.16 TeV

Anelli A.;Borsato M.;Calvi M.;Capelli S.;Carniti P.;Falcao L. N.;Fazzini D.;Garcia Pardinas J.;Gotti C.;Kirsebom V. S.;Malentacca L.;Martinazzoli L.;Martinelli M.;Minotti A.;Pizzichemi M.;Salomoni M.;
2025

Abstract

The production ratio of ψ(2S) to J/ψ charmonium states is presented as a function of multiplicity in proton-lead collisions at a centre-of-mass energy of sNN=8.16 TeV, for both prompt and nonprompt sources. The total luminosity recorded by the LHCb experiment corresponds to 13.6 nb−1 for pPb collisions and 20.8 nb−1 for Pbp collisions, where the first particle corresponds to the particle traveling towards the detector. Measurements are performed in the dimuon final state at forward (backward) centre-of-mass rapidity, with respect to the proton direction, 1.5 < y*< 4.0 (−5.0 < y*< −2.5) for pPb (Pbp) collisions. A multiplicity dependence of the prompt production ratio is observed in pPb collisions, whereas no dependence is found in nonprompt production, nor in either prompt or nonprompt production in Pbp collisions. These results suggest that in the Pb-going direction additional suppression mechanisms beyond comover effects may be present, possibly related to the formation of quark-gluon plasma. This highlights a transition from small to large collision systems and provides important insight into the suppression of charmonia in proton-nucleus collisions.
Articolo in rivista - Articolo scientifico
Heavy Ion Experiments; Heavy-Ion Collision; Quarkonium;
English
26-nov-2025
2025
2025
11
169
none
Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2025). Measurement of ψ(2S) to J/ψ cross-section ratio as function of multiplicity in pPb collisions at sNN=8.16 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2025(11) [10.1007/JHEP11(2025)169].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/591003
Citazioni
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 0
Social impact