Leading-particle suppression and surface emission in nucleus-nucleus   collisions
  After a short summary of the predictions of the Parton Quenching Model (PQM) for the nuclear modification factor and its centrality dependence in Au-Au collisions at RHIC, we concentrate on back-to-back jet-like correlations at high transverse momentum. We illustrate how this probe is biased by the surface effect. 
Andrea Dainese (Padova U. and INFN), Constantin Loizides (MIT) and Guy   Paic (Mexico City U., ICN)