Jet shape and fragmentation function measurements with CMS

We present measurements of the jet fragmentation functions and transverse momentum profiles (shapes) in PbPb collisions at 2.76 TeV per nucleon-pair center of mass energy with the CMS detector. Jets are reconstructed by the anti-$k_{T}$ sequential clustering algorithm with a resolution parameter of 0.3, using particle-flow objects that combine tracking and calorimetric information. In this talk the jet properties of inclusive jets with transverse momentum $p_{T} >$ 100 GeV/c in PbPb collisions are measured for reconstructed charged particles with $p_{T}$~ $>$ 1 GeV/c in a cone of radius $\sqrt{{\Delta \phi}^{2}+{\Delta \eta}^{2}} = $ 0.3 around the jet axis. A data sample of \PbPb\ collisions collected in 2011 at a center-of-mass energy of $\sqrt{s_{_{NN}}}= 2.76$~TeV corresponding to an integrated luminosity of 150 $\mu b^{-1}$ is used. The results for PbPb collisions as a function of collision centrality are compared to reference distributions based on the full 2013 pp statistics collected at the same collision energy. Centrality-dependent modifications of the fragmentation functions and shapes are revealed.