  We construct an evolution equation for the invariant-mass distribution of
light-quark and gluon jets in the framework of QCD resummation. The solution of
the evolution equation exhibits a behavior consistent with Tevatron CDF data:
the jet distribution vanishes in the small invariant-mass limit, and its peak
moves toward the high invariant-mass region with the jet energy. We also
construct an evolution equation for the energy profile of the light-quark and
gluon jets in the similar framework. The solution shows that the energy
accumulates faster within a light-quark jet cone than within a gluon jet cone.
The jet energy profile convoluted with hard scattering and parton distribution
functions matches well with the Tevatron CDF and the large-hadron-collider
(LHC) CMS data. Moreover, comparison with the CDF and CMS data implies that
jets with large (small) transverse momentum are mainly composed of the
light-quark (gluon) jets. At last, we discuss the application of the above
solutions for the light-particle jets to the identification of highly-boosted
heavy particles produced at LHC.
