Study of J/psi meson production inside jets in pp collisions at N root s=8 TeV The CM Collaboration

Sirunyan A. M., Tumasyan A., Adam W., Ambrogi F., Asilar E., Bergauer T., ...More

PHYSICS LETTERS B, vol.804, 2020 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 804
  • Publication Date: 2020
  • Doi Number: 10.1016/j.physletb.2020.135409
  • 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
  • Keywords: CMS, J/psi Mesons, Jets
  • Middle East Technical University Affiliated: Yes


A study of the production of prompt J/psi mesons contained in jets in proton-proton collisions at root s = 8 TeV is presented. The analysis is based on data corresponding to an integrated luminosity of 19.1 fb(-1) collected with the CMS detector at the LHC. For events with at least one observed jet, the angular separation between the J/psi meson and the jet is used to test whether the J/psi meson is part of the jet. The analysis shows that most prompt J/psi mesons having energy above 15 GeV and rapidity vertical bar y vertical bar < 1 are contained in jets with pseudorapidity vertical bar eta(jet)vertical bar < 1. The differential distributions of the probability to have a J/psi meson contained in a jet as a function of jet energy for a fixed J/psi energy fraction are compared to a theoretical model using the fragmenting jet function approach. The data agree best with fragmenting jet function calculations that use a long-distance matrix element parameter set in which prompt J/psi mesons are predicted to be unpolarized. This technique demonstrates a new way to test predictions for prompt J/psi production using nonrelativistic quantum chromodynamics. (C) 2020 Elsevier B.V.