  Measurements of the nuclear modification factor of inclusive yields of
$\pi^0$, $p\bar{p}$, non-phtonic electrons and prompt photon measured at RHIC
are reviewed. Some of the difficulties arising from interpretation of these
measurements such as similarity of the suppression pattern of light and heavy
quarks, quarks and gluons, light quarks and prompt photon are discussed. The
potential of two-particle and promt photon correlation technique to unravel
some of these open questions is presented. An emphasis is given to the
influence of partonic transverse momentum on the prompt-photon correlations.
The smearing between the trigger photon and back-to-back jet at LHC energy is
discussed.
