TY  - INPR
T1  - Measurement of the J/ψ polarization with respect to the event plane in Pb–Pb collisions at the LHC
T2  - arXiv
N2  - The polarization of inclusive J/ψ produced in Pb-Pb collisions at sNN−−−√=5.02 TeV at the LHC was studied by ALICE in the dimuon channel, via the measurement of the angular distribution of its decay products. The study was performed 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 was 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 existence of a strong magnetic field in the early stage of quark-gluon plasma formation in Pb-Pb collisions, as well as with its behaviour as a rotating fluid with large vorticity.
T3  - CERN Report - CERN-EP-2022-066 
Y1  - 2022
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/80119
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-801199
UR  - https://arxiv.org/abs/2204.10171v1
IS  - 2204.10171 Version 1
PB  - arXiv
ER  -