Naslov
Indications of Suppression of Excited Υ States in Pb-Pb Collisions at √sNN=2.76  TeV

Autori
Chatrchyan, S. ; ... ; Godinović, Nikola ; Lelas, Karlo ; Pleština, Roko ; Polić, Dunja ; Puljak, Ivica ; Antunović, Željko ; Dželalija, Mile ; Brigljević, Vuko ; Đurić, Senka ; Kadija, Krešo ; Morović, Srećko ; ... ; White, A.

Izvornik
Physical Review Letters (0031-9007) 107 (2011), 052302; 1-15

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
CERN; CMS; LHC

Sažetak
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%.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
The CMS Collaboration

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