  We report the measurements of nuclear modification factors of the Z bosons,
isolated photons and charged particles in $\sqrt{s_{NN}}$ = 2.76 TeV PbPb
collisions with the CMS detector. The nuclear modification factors are
constructed by dividing the PbPb $p_T$ spectra, normalized to the number of
binary collisions, by the pp references. No modifications are observed in
isolated photon and Z boson production with respected to the pp references
while large suppression is observed in the charged particles.
