Observation of the Charged-Particle Multiplicity Dependence of σ_{ψ(2S)}/σ_{J/ψ} in p-Pb Collisions at 8.16 TeV


Chekhovsky V., Hayrapetyan A., Makarenko V., Tumasyan A., Adam W., Andrejkovic J., ...More

Physical review letters, vol.135, no.9, pp.92301, 2025 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 135 Issue: 9
  • Publication Date: 2025
  • Doi Number: 10.1103/c9wp-5tq3
  • Journal Name: Physical review letters
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Compendex, INSPEC, zbMATH, DIALNET, Nature Index
  • Page Numbers: pp.92301
  • Istanbul University Affiliated: Yes

Abstract

Bound states of charm and anticharm quarks, known as charmonia, have a rich spectroscopic structure that can be used to probe the dynamics of hadron production in high-energy hadron collisions. Here, the cross section ratio of excited (ψ(2S)) and ground state (J/ψ) vector mesons is measured as a function of the charged-particle multiplicity in proton-lead (pPb) collisions at a center-of-mass (CM) energy per nucleon pair of 8.16 TeV. The data corresponding to an integrated luminosity of 175 nb^{-1} were collected using the CMS detector. The ratio is measured separately for prompt and nonprompt charmonia in the transverse momentum range 6.5