Jet investigations using the radial moment

We define the radial moment {l_angle}r{r_angle} for jets produced in hadron-hadron collisions. It can be used as a tool for studying, as a function of the jet transverse energy and pseudorapidity, radiation {ital within} the jet and the quality of a perturbative description of the jet shape. We also discuss how nonperturbative corrections to the jet transverse energy affect {l_angle}r{r_angle}. {copyright} {ital 1997} {ital The American Physical Society}