  The non-Abelian feature of quantum chromodynamics (QCD) results in the gluons
losing more energy than quarks in the medium formed in high energy heavy-ion
collisions. Experimental results in p+p collisions when compared to NLO pQCD
calculations show that at high transverse momentum (pT) the produced
protons+anti-protons are dominantly from gluon jets and charged pions have
substantial contribution from quark jets. If such a scenario is applied to
heavy-ion collisions at RHIC, one would expect the difference in quark and
gluon energy loss to have an effect on measured observables, such as high pT
pbar(p)/pi ratios and the nuclear modification factor for various particles
species. We discuss the experimental results and some possible future
measurements.
