Speaker
Guillermo Breto Rangel
(University of California Davis (US))
Description
The three Y states (1S, 2S, 3S) can be separated using the CMS experimental apparatus via their dimuon decays in both pp and heavy-ion collisions. A suppression of the Y(1S) and Y(2S) mesons is observed in PbPb collisions at sqrt(sNN) = 2.76 TeV, compared to the yield in pp collisions scaled by the number of inelastic nucleon-nucleon collisions. Furthermore, a suppression of the excited Y states has been measured with respect to the Y(1S) state, expressed as a double ratio [Y(2S+3S)/Y(1S)]{PbPb} / [Y(2S+3S)/Y(1S)]{pp}. The centrality dependence of the double ratio, as well as the nuclear modification factors (RAA) of the Y(1S) and Y(2S) states will be 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 150/ub.
Primary author
Collaboration CMS
(CERN)
