Centrality and transverse momentum dependence of inclusive J/psi production at midrapidity in Pb-Pb collisions at root s NN=5 .02 TeV

Acharya S., Adamova D., Adler A., Adolfsson J., Aggarwal M. M., Rinella G. A., ...More

PHYSICS LETTERS B, vol.805, 2020 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 805
  • Publication Date: 2020
  • Doi Number: 10.1016/j.physletb.2020.135434
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, INSPEC, zbMATH, Directory of Open Access Journals
  • Bursa Uludag University Affiliated: No


The inclusive J/$\psi$ meson production in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon collision of $\sqrt{s_{\rm NN}}$ = 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/$\psi$ transverse momentum $p_{\rm T}$, down to $p_{\rm T}$ = 0 GeV/$c$. The J/$\psi$ mean transverse momentum $\langle p_{\rm T} \rangle$ and $r_{\rm AA}$ ratio, defined as $\langle p^{\rm 2}_{\rm T} \rangle_{\rm PbPb}/\langle p^{\rm 2}_{\rm T} \rangle_{\rm pp}$, are evaluated. Both observables show a centrality dependence decreasing towards central (head-on) collisions. The J/$\psi$ nuclear modification factor $R_{\rm AA}$ exhibits a strong $p_{\rm T}$ dependence with a large suppression at high $p_{\rm T}$ and an increase to unity for decreasing $p_{\rm T}$. When integrating over the measured momentum range $p_{\rm T}$ < 10 GeV/$c$, the J/$\psi$ $R_{\rm AA}$ 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/$\psi$ production at low $p_{\rm T}$ are consistent with a dominant contribution to the J/$\psi$ yield originating from charm quark (re)combination.