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Title
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Investigation into the event-activity dependence of Υ(nS) relative production in proton-proton collisions at √s=7 TeV
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Author
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Institution/Organisation
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CMS Collaboration
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Abstract
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| The ratios of the production cross sections between the excited gamma(2S) and gamma(3S) mesons and the gamma(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 root s = 7TeV, 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 p(T)(mu mu). For gamma(nS) mesons with p(T)(mu mu) > 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 gamma(nS) direction. The ratios are found to be multiplicity independent for jet-like events. The mean p(T)(mu mu) values for the gamma(nS) states as a function of particle multiplicity are also measured and found to grow more steeply as their mass increases. |
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Language
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English
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Source (journal)
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Journal of high energy physics. - Bristol
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Publication
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Bristol
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2020
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ISSN
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1126-6708
1029-8479
[online]
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DOI
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10.1007/JHEP11(2020)001
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Volume/pages
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11
(2020)
, 39 p.
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Article Reference
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001
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ISI
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000585126400001
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Medium
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E-only publicatie
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Full text (Publisher's DOI)
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Full text (open access)
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