A1 Journal article (refereed)
ψ(2S) suppression in Pb-Pb collisions at the LHC (2024)

ALICE collaboration. (2024). ψ(2S) suppression in Pb-Pb collisions at the LHC. Physical Review Letters, 132, Article 042301. https://doi.org/10.1103/PhysRevLett.132.042301

JYU authors or editors

Publication details

All authors or editors: ALICE collaboration

Journal or series: Physical Review Letters

ISSN: 0031-9007

eISSN: 1079-7114

Publication year: 2024

Publication date: 24/01/2024

Volume: 132

Article number: 042301

Publisher: American Physical Society (APS)

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevLett.132.042301

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/95157

Publication is parallel published: https://arxiv.org/abs/2210.08893

Abstract

The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at √sNN=5.02 TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5<4). The measurement of the ratio of the inclusive production cross sections of the ψ(2S) and J/ψ resonances is reported as a function of the centrality of the collisions and of transverse momentum, in the region pT<12 GeV/c. The results are compared with the corresponding measurements in pp collisions, by forming the double ratio [σψ(2S)/σJ/ψ]Pb−Pb/[σψ(2S)/σJ/ψ]pp. It is found that in Pb-Pb collisions the ψ(2S) is suppressed by a factor of ∼2 with respect to the J/ψ. The ψ(2S) nuclear modification factor RAA was also obtained as a function of both centrality and pT. The results show that the ψ(2S) resonance yield is strongly suppressed in Pb-Pb collisions, by a factor up to ∼3 with respect to pp. Comparisons of cross section ratios with previous SPS findings by the NA50 experiment and of RAA with higher-pT results at LHC energy are also reported. These results and the corresponding comparisons with calculations of transport and statistical models address questions on the presence and properties of charmonium states in the quark-gluon plasma formed in nuclear collisions at the LHC.

Keywords: nuclear physics; particle physics

Free keywords: color confinement; relativistic heavy-ion collisions; quarkonia

Contributing organizations

Related projects

Ministry reporting: Yes

Preliminary JUFO rating: 3