Compact Muon Solenoid
LHC, CERN
Visit us: CMS Public Website, CMS Physics ;
Contact us: CMS Publications Committee
| CMS-HIN-11-007 ; CERN-PH-EP-2011-074 | ||
| Indications of Suppression of Excited $\Upsilon$ States in Pb-Pb Collisions at $\sqrt{s_{NN}}$ = 2.76 TeV | ||
| CMS Collaboration | ||
| 26 May 2011 | ||
| Phys. Rev. Lett. 107 (2011) 052302 | ||
| Abstract: A comparison of the relative yields of Upsilon resonances in the mu(+) mu(-) decay channel in PbPb and pp collisions at a centre-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 Upsilon(2S) and Upsilon(3S) excited states to the Upsilon(1S) ground state in PbPb and pp collisions,(Upsilon(2S+3S)/Upsilon(1S)[PbPb])/(Upsilon(2S+3S)/Upsilon(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, has been calculated to be less than 1%. | ||
| Links: e-print arXiv:1105.4894 [nucl-ex] (PDF) ; CDS record ; inSPIRE record ; Public twiki page ; CADI line (restricted) ; | ||
| Figures | |
png pdf |
Figure 1-a:
|
png pdf |
Figure 1-b:
|
|
|
Compact Muon Solenoid LHC, CERN |
|
|
|
|
|
|