\ Nuclear modification factor \raa for isolated photons at \snnfive for the 50--90\% centrality class, and for isolation-cone radii $R=0.2$ (black) and $R=0.4$ (blue). In data, the denominator is replaced by the \pp collisions NLO pQCD calculation with JETPHOX Error bars and boxes are the statistical and systematic uncertainties, respectively. The bands correspond to pQCD calculations with JETPHOX for \PbPb collisions (nPDF) for 0--100\% centrality over pp collisions (PDF). The pQCD band ratio is shown only for $R=0.2$ (similar to $R=0.4$) The width of each band corresponds to the scale and PDF uncertainties The normalisation uncertainties are represented as a red box centred at unity The solid line in the most peripheral centrality class 70--90\% at \raa = 0.91 corresponds to the HG-PYTHIA model expectation .