We perform a joint analysis of the data from PHENIX at RHIC and ALICE at LHC on the nuclear modification factor $R_{ AA}$. The computations are performed within the light-cone path integral approach to induced gluon emission. Our results show that slow variation of $R_{ AA}$ from RHIC to LHC energies indicates that the QCD coupling constant is suppressed in the quark-gluon plasma produced at LHC.
Categories: hep-ph nucl-th