Jets in inclusive e⁺e^- and leptoproduction

The assumption of jets with bounded p_T leads to the following consequences: (a) In e⁺e^- annihilation the coefficient of the cos²θ term (a) of single-particle inclusive distributions] exhibits a unique dependence on the observed particle momentum. This dependence provides a measure of 〈p_T²〉 in a jet. (b) In two-particle inclusive annihilation the average of the squared relative p_T is determined by the same parameter and by the momenta of the two particles. (c) The observation that in the current fragmentation region of leptoproduction the p_T distribution of fast hadrons is broader than that of show ones is explained.