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.

(2020). Investigation into the event-activity dependence of ϒ(nS) relative production in proton-proton collisions at √s = 7 TeV [journal article - articolo]. In JOURNAL OF HIGH ENERGY PHYSICS. Retrieved from http://hdl.handle.net/10446/168918

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

Re, V.;Vai, I.;
2020-01-01

Abstract

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.
articolo
2020
Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Bergauer, T.; Dragicevic, M.; Erö, J.; Escalante Del Valle, A.; Flechl, M.; Frühwirth, R.; Jeitl...espandi
(2020). Investigation into the event-activity dependence of ϒ(nS) relative production in proton-proton collisions at √s = 7 TeV [journal article - articolo]. In JOURNAL OF HIGH ENERGY PHYSICS. Retrieved from http://hdl.handle.net/10446/168918
File allegato/i alla scheda:
File Dimensione del file Formato  
Sirunyan2020_Article_InvestigationIntoTheEvent-acti.pdf

accesso aperto

Versione: publisher's version - versione editoriale
Licenza: Creative commons
Dimensione del file 1.14 MB
Formato Adobe PDF
1.14 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Aisberg ©2008 Servizi bibliotecari, Università degli studi di Bergamo | Terms of use/Condizioni di utilizzo

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10446/168918
Citazioni
  • Scopus 17
  • ???jsp.display-item.citation.isi??? 14
social impact