Measurement of the J/ψ polarization with respect to the event plane in Pb-Pb collisions at the LHC
We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at √sNN=5.02 TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.5<y<4, for three transverse momentum intervals (2<p...
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| Main Authors: | , , , , , , , , , , , , , , , , , , , , |
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| Corporate Author: | |
| Format: | Article (Journal) |
| Language: | English |
| Published: |
25 July 2023
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| In: |
Physical review letters
Year: 2023, Volume: 131, Issue: 4, Pages: 1-13 |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/PhysRevLett.131.042303 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.1103/PhysRevLett.131.042303 Verlag, kostenfrei, Volltext: https://link.aps.org/doi/10.1103/PhysRevLett.131.042303 |
| Author Notes: | S. Acharya et al. (ALICE Collaboration)* |
| Summary: | We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at √sNN=5.02 TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.5<y<4, for three transverse momentum intervals (2<pT<4, 4<pT<6, 6<pT<10 GeV/c) and as a function of the centrality of the collision for 2<pT<6 GeV/c. For the first time, the polarization is measured with respect to the event plane of the collision, by considering the angle between the positive-charge decay muon in the J/ψ rest frame and the axis perpendicular to the event-plane vector in the laboratory system. A small transverse polarization is measured, with a significance reaching 3.9σ at low pT and for intermediate centrality values. The polarization could be connected with the behavior of the quark-gluon plasma, formed in Pb-Pb collisions, as a rotating fluid with large vorticity, as well as with the existence of a strong magnetic field in the early stage of its formation. |
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| Item Description: | *ALICE Collaboration: S. Acharya, V. Anguelov, A. Berdnikova, L. Bergmann, M.C. Danisch, V.J.G. Feuillard, I. Fokin, P. Glässel, M. Kroesen, A. Nath, Y. Pachmayer, K. Reygers, R. Schicker, G. Skorodumovs, J. Stachel, S.F. Stiefelmaier, C.A. van Veen, M.A. Völkl, B. Windelband, A. Yuncu, F. Zanone [und 1010 weitere Personen] Gesehen am 14.02.2024 |
| Physical Description: | Online Resource |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/PhysRevLett.131.042303 |