Nuclear modification factors from the CMS experiment

Understand

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.