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ψ (2S) Suppression in Pb-Pb Collisions at the LHC

Acharya, S. ; Basu, S. LU orcid ; Christiansen, P. LU ; Matonoha, O. LU ; Nassirpour, A.F. LU orcid ; Ohlson, A. LU ; Rueda, O.V. LU ; Silvermyr, D. LU orcid ; Staa, J. LU and Zugravel, S.C. , et al. (2024) In Physical Review Letters 132(4).
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<y<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.... (More)
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<y<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 of up to ∼3 with respect to pp. Comparisons of cross section ratios with previous Super Proton Synchrotron 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. (Less)
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author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Germanium alloys, Lead alloys, Charmonium, Decay channels, Energy, Forward rapidity, Measurements of, Nuclear modification factors, Pb-Pb collisions, Production cross section, Super proton synchrotrons, Transverse momenta, article, controlled study, nonhuman, Binary alloys
in
Physical Review Letters
volume
132
issue
4
article number
042301
publisher
American Physical Society
external identifiers
  • scopus:85184287111
  • pmid:38335364
ISSN
0031-9007
DOI
10.1103/PhysRevLett.132.042301
language
English
LU publication?
yes
id
ad7458ac-7c62-4e54-bf96-26677f21bebe
date added to LUP
2024-03-12 14:46:56
date last changed
2024-03-14 03:04:10
@article{ad7458ac-7c62-4e54-bf96-26677f21bebe,
  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&lt;y&lt;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&lt;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 of up to ∼3 with respect to pp. Comparisons of cross section ratios with previous Super Proton Synchrotron 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.}},
  author       = {{Acharya, S. and Basu, S. and Christiansen, P. and Matonoha, O. and Nassirpour, A.F. and Ohlson, A. and Rueda, O.V. and Silvermyr, D. and Staa, J. and Zugravel, S.C. and Zurlo, N.}},
  issn         = {{0031-9007}},
  keywords     = {{Germanium alloys; Lead alloys; Charmonium; Decay channels; Energy; Forward rapidity; Measurements of; Nuclear modification factors; Pb-Pb collisions; Production cross section; Super proton synchrotrons; Transverse momenta; article; controlled study; nonhuman; Binary alloys}},
  language     = {{eng}},
  number       = {{4}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review Letters}},
  title        = {{ψ (2S) Suppression in Pb-Pb Collisions at the LHC}},
  url          = {{http://dx.doi.org/10.1103/PhysRevLett.132.042301}},
  doi          = {{10.1103/PhysRevLett.132.042301}},
  volume       = {{132}},
  year         = {{2024}},
}