I will summarize the available data on hadronic final states in high-energy electron–nucleon scattering, with emphasis on the most recent experiments in the deep inelastic scaling region.
Recent work on \(e^+e^-\) annihilation by Cabibbo, Wolfenstein and the author is reviewed. The restrictions of unitarity are analyzed and the connection between the cross sections \(\sigma _h\) into hadrons) and \(\sigma _\mu \), (into muons) is derived. The possibility of non-scaling in \(e^+e^-\) annihilation is studied and it is pointed out that it leads to no contradiction with presently available information. It is further pointed out that non-scaling could provide a cut-off mechanism for Quantum Electrodynamics.
Some theoretical aspects of the subject of high-\(p_\perp \) hadron production in strong interactions are discussed. This includes properties of inclusive spectra, the parent-child relation and its applications to direct lepton and \(\gamma \)-ray production. Also discussed are hypotheses regarding the phase-space populations of associated particles, correlations and production of jets. Dynamical models are only very briefly discussed, and suggestions for future experimentation are listed.