Investigation into the event-activity dependence of ϒ(nS) relative production in proton-proton collisions at √s = 7 TeV

Link:
Erscheinungsjahr:
2020
Medientyp:
Text
Schlagworte:
  • Ionic Collisions
  • Relativistic Heavy-ion Collisions
  • Quark-Gluon Plasma
  • Decay
  • Quarks
  • Neutrinos
  • Ionic Collisions
  • Relativistic Heavy-ion Collisions
  • Quark-Gluon Plasma
  • Decay
  • Quarks
  • Neutrinos
Beschreibung:
  • The ratios of the production cross sections between the excited Υ(2S) and Υ(3S) mesons and the Υ(1S) ground state, detected via their decay into two muons, are studied as a function of the number of charged particles in the event. The data are from proton-proton collisions at s√= 7 TeV, corresponding to an integrated luminosity of 4.8 fb−1, collected with the CMS detector at the LHC. Evidence of a decrease in these ratios as a function of the particle multiplicity is observed, more pronounced at low transverse momentum pμμT. For Υ(nS) mesons with pμμT > 7 GeV, where most of the data were collected, the correlation with multiplicity is studied as a function of the underlying event transverse sphericity and the number of particles in a cone around the Υ(nS) direction. The ratios are found to be multiplicity independent for jet-like events. The mean pμμT values for the Υ(nS) states as a function of particle multiplicity are also measured and found to grow more steeply as their mass increases.
Lizenz:
  • info:eu-repo/semantics/openAccess
Quellsystem:
Forschungsinformationssystem der UHH

Interne Metadaten
Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/1a9a6243-0fa9-4257-9754-e329fe99c00e