Centrality and transverse momentum dependence of inclusive J/ψ production at midrapidity in Pb–Pb collisions at sNN=5.02 TeV

Summary, in English

The inclusive J/ψ meson production in Pb–Pb collisions at a center-of-mass energy per nucleon–nucleon collision of sNN=5.02 TeV at midrapidity (|y|<0.9) is reported by the ALICE Collaboration. The measurements are performed in the dielectron decay channel, as a function of event centrality and J/ψ transverse momentum pT, down to pT=0. The J/ψ mean transverse momentum 〈pT〉 and rAA ratio, defined as 〈pT2〉PbPb/〈pT2〉pp, are evaluated. Both observables show a centrality dependence decreasing towards central (head-on) collisions. The J/ψ nuclear modification factor RAA exhibits a strong pT dependence with a large suppression at high pT and an increase to unity for decreasing pT. When integrating over the measured momentum range pT<10 GeV/c, the J/ψ RAA shows a weak centrality dependence. Each measurement is compared with results at lower center-of-mass energies and with ALICE measurements at forward rapidity, as well as to theory calculations. All reported features of the J/ψ production at low pT are consistent with a dominant contribution to the J/ψ yield originating from charm quark (re)combination. © 2020 European Organization for Nuclear Research

• Author: Acharya S.; J. Adolfsson; P. Christiansen; O. Matonoha; A. Nassirpour; A. Ohlson; A. Oskarsson; T. Richert; Oscar M Rueda; D. Silvermyr; E. Stenlund; Zurlo N.
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2020
• Language: English
• Publication/Series: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 805
• Links: http://dx.doi.org/10.1016/j.physletb.2020.135434
• Document type: Journal article
• Publisher: Elsevier
• Topic: Physical Sciences
• Status: Published
• ISBN/ISSN/Other: ISSN: 0370-2693