Nuclear modification factor for gluon jets
  It is shown that the nuclear modification factor can be smaller that unity for jet production at small $x$ and at large transverse momentum without any violation of the factorization theorem and the initial state effects is able to explain the nuclear modification factor of the order of the one measured by ATLAS. In other word, initial state effects are able to describe the jet quenching for the gluon jet production. 
Eugene Levin (Tel Aviv Un./UTSFT)
hep-ph