  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%.
