Observation of Sequential upsilon Suppression in PbPb Collisions
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
30/09/2013
20/05/2014
30/09/2013
20/05/2014
26/11/2012
|
Resumo |
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The suppression of the individual gamma (nS) states in PbPb collisions with respect to their yields in pp data has been measured. The PbPb and pp data sets used in the analysis correspond to integrated luminosities of 150 mu b(-1) and 230 nb(-1), respectively, collected in 2011 by the CMS experiment at the LHC, at a center-of-mass energy per nucleon pair of 2.76 TeV. The gamma (nS) yields are measured from the dimuon invariant mass spectra. The suppression of the gamma (nS) yields in PbPb relative to the yields in pp, scaled by the number of nucleon-nucleon collisions, R-AA, is measured as a function of the collision centrality. Integrated over centrality, the R-AA values are 0.56 +/- 0.08(stat) +/- 0.07(syst), 0.12 +/- 0.04(stat) +/- 0.02(syst), and lower than 0.10 (at 95% confidence level), for the gamma (1S), gamma (2S), and gamma (3S) states, respectively. The results demonstrate the sequential suppression of the gamma (nS) states in PbPb collisions at LHC energies. |
Formato |
15 |
Identificador |
http://dx.doi.org/10.1103/PhysRevLett.109.222301 Physical Review Letters. College Pk: Amer Physical Soc, v. 109, n. 22, p. 15, 2012. 0031-9007 http://hdl.handle.net/11449/24669 10.1103/PhysRevLett.109.222301 WOS:000311552100002 WOS000311552100002.pdf |
Idioma(s) |
eng |
Publicador |
Amer Physical Soc |
Relação |
Physical Review Letters |
Direitos |
openAccess |
Tipo |
info:eu-repo/semantics/article |