  We provide a novel development in jet physics by predicting the energy
profiles of light-quark and gluon jets in the framework of perturbative QCD.
Resumming large logarithmic contributions to all orders in the coupling
constant, our predictions are shown to agree well with Tevatron CDF and
Large-Hadron-Collider CMS data. We also extend our resummation formalism to the
invariant mass distributions of light-quark and gluon jets produced in hadron
collisions. The predicted peak positions and heights in jet mass distributions
are consistent with CDF data within uncertainties induced by parton
distribution functions.
