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Title: Measurement of Prompt $$\psi(2S) \to J/\psi$$ Yield Ratios in Pb-Pb and $p-p$ Collisions at $$\sqrt {s_{NN}}=$$ 2.76 TeV

The ratio between the prompt ψ(2S) and J/ψ yields, reconstructed via their decays into μ+μ-, is measured in Pb-Pb and p-p collisions at √sNN=2.76 TeV. Likewise, the analysis is based on Pb-Pb and p-p data samples collected by CMS at the Large Hadron Collider, corresponding to integrated luminosities of 150 μb-1 and 5.4 pb-1, respectively. The double ratio of measured yields (Nψ(2S)/NJ/ψ)Pb-Pb/(Nψ(2S)/NJ/ψ)p-p is computed in three Pb-Pb collision centrality bins and two kinematic ranges: one at midrapidity, |y|<1.6, covering the transverse momentum range 6.5T<30 GeV/c, and the other at forward rapidity, 1.6<|y|<2.4, extending to lower pT values, 3T<30 GeV/c. Furthermore, the centrality-integrated double ratio changes from 0.45±0.13(stat)±0.07(syst) in the first range to 1.67±0.34(stat)±0.27(syst) in the second. This difference is most pronounced in the most central collisions.
Authors:
 [1]
  1. Yerevan Physics Inst. (YerPhI) (Armenia). et al.
Publication Date:
OSTI Identifier:
1180945
Report Number(s):
FERMILAB-PUB-14-445-CMS; CERN-PH-EP-2014-240; CMS-HIN-12-007
Journal ID: ISSN 0031-9007; arXiv eprint number arXiv:1410.1804; TRN: US1600800
Grant/Contract Number:
AC02-07CH11359
Type:
Published Article
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 113; Journal Issue: 26; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5)
Contributing Orgs:
CMS Collaboration
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS