Abstract :
The three ϒ states (1S, 2S, 3S) were separated using the Compact Muon Solenoid (CMS) experimental apparatus via their dimuon decays in both pp and heavy-ion collisions. A suppression of the image, image and image mesons is observed in PbPb collisions at image, compared to the yield in pp collisions scaled by the number of inelastic nucleon–nucleon collisions. Furthermore, a suppression of the excited image state has been measured with respect to the image state, expressed as a double ratio image. The centrality dependence of the double ratio, as well as the nuclear modification factors (image) of the image and image states are presented as a function of collision centrality, based on the analysis of the full data sample collected during the 2011 PbPb run, which corresponds to an integrated luminosity of image. Upper limits for image, for both the image and the double ratio, were also calculated.
