Jet calculus rules

Abstract

We present the recent developments in the QCD description of hard processes. i.e., the jet calculus. It describes the multi-particle spectra in a single jet from the parton interpretation of each contributing diagrams in the leading log approximation of QCD and in the axial gauge. We present the derivation of the rules and the application of these rules to the quark and gluon jets, which gives a test of QCD.