In:
Journal of High Energy Physics, Springer Science and Business Media LLC, Vol. 2020, No. 11 ( 2020-11)
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 $$ \sqrt{s} $$ 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 $$ {p}_{\mathrm{T}}^{\upmu \upmu} $$ p T μμ . For ϒ(nS) mesons with $$ {p}_{\mathrm{T}}^{\upmu \upmu} $$ p T μμ 〉 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 $$ {p}_{\mathrm{T}}^{\upmu \upmu} $$ p T μμ 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.
Type of Medium:
Online Resource
ISSN:
1029-8479
DOI:
10.1007/JHEP11(2020)001
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
2027350-2
