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


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Sirunyan A., Tumasyan A., Adam W., Ambrogi F., Bergauer T., Dragicevic M., ...Daha Fazla

Journal of High Energy Physics, cilt.2020, sa.11, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 2020 Sayı: 11
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1007/jhep11(2020)001
  • Dergi Adı: Journal of High Energy Physics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, INSPEC, zbMATH, Directory of Open Access Journals
  • Anahtar Kelimeler: B physics, Hadron-Hadron scattering (experiments), Particle correlations and fluctuations, Quarkonium
  • Erzincan Binali Yıldırım Üniversitesi Adresli: Evet

Özet

© 2020, The Author(s).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 pTμμ. For ϒ(nS) mesons with pTμμ> 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 pTμμ 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. [Figure not available: see fulltext.]