Figure 2

Nuclear modification factor $R_{\rm{AA}} $ of charged particles measured in Pb-Pb collisions in nine centrality intervals. The boxes around data points denote $p_{{\rm T}}$-dependent systematic uncertainties. The systematic uncertainties on the normalization which are related to $\langle T_{\rm{AA}} \rangle$ and the normalization of the pp data are added in quadrature and shown as boxes at $R_{\rm{AA}} =1$.