A comparison of the relative yields of Υ resonances in the μ+μ- decay channel in Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair of 2.76 TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4  GeV/c and pseudorapidity below 2.4, the double ratio of the Υ(2S) and Υ(3S) excited states to the Υ(1S) ground state in Pb-Pb and pp collisions, [Υ(2S+3S)/Υ(1S)]Pb-Pb/[Υ(2S+3S)/Υ(1S)]pp, is found to be 0.31-0.15+0.19(stat)±0.03(syst). The probability to obtain the measured value, or lower, if the true double ratio is unity, is calculated to be less than 1%.

V. KHACHATRYAN, A.M. SIRUNYAN, A. TUMASYAN, W. ADAM, T. BERGAUER, M. DRAGICEVIC, et al. (2011). Indications of Suppression of Excited Upsilon States in Pb-Pb Collisions at sqrt(s)=2.76 TeV. PHYSICAL REVIEW LETTERS, 107, 052302-1-052302-15 [10.1103/PhysRevLett.107.052302].

Indications of Suppression of Excited Upsilon States in Pb-Pb Collisions at sqrt(s)=2.76 TeV

BONACORSI, DANIELE;BRAIBANT, SYLVIE;CAPILUPPI, PAOLO;CASTRO, ANDREA;CUFFIANI, MARCO;FANFANI, ALESSANDRA;FASANELLA, DANIELE;MENEGHELLI, MARCO;NAVARRIA, FRANCESCO LUIGI;ROSSI, ANTONIO MARIA;ROVELLI, TIZIANO;SIROLI, GIAN PIERO;GUIDUCCI, LUIGI;PRIMAVERA, FEDERICA;BRIGLIADORI, LUCA
2011

Abstract

A comparison of the relative yields of Υ resonances in the μ+μ- decay channel in Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair of 2.76 TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4  GeV/c and pseudorapidity below 2.4, the double ratio of the Υ(2S) and Υ(3S) excited states to the Υ(1S) ground state in Pb-Pb and pp collisions, [Υ(2S+3S)/Υ(1S)]Pb-Pb/[Υ(2S+3S)/Υ(1S)]pp, is found to be 0.31-0.15+0.19(stat)±0.03(syst). The probability to obtain the measured value, or lower, if the true double ratio is unity, is calculated to be less than 1%.
2011
V. KHACHATRYAN, A.M. SIRUNYAN, A. TUMASYAN, W. ADAM, T. BERGAUER, M. DRAGICEVIC, et al. (2011). Indications of Suppression of Excited Upsilon States in Pb-Pb Collisions at sqrt(s)=2.76 TeV. PHYSICAL REVIEW LETTERS, 107, 052302-1-052302-15 [10.1103/PhysRevLett.107.052302].
V. KHACHATRYAN; A.M. SIRUNYAN; A. TUMASYAN; W. ADAM; T. BERGAUER; M. DRAGICEVIC; J. ER¨O; C. FABJAN; M. FRIEDL; R. FRUHWIRTH; V.M. GHETE; J. HAMMER; S...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/119164
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