Basic regge theory

This series of lectures on basic Regge theory were presented as part of a course for postgraduate experimental high energy physicists. It is shown that Regge theory rules high-energy production just as well as 2 → 2 processes. However exclusive applications and tests are hampered by lack of events and phase space, but the multi-Regge model is more than a toy. The method describes well inclusive scaling and its approach, including development of a central plateau (and the associated rise of mean multiplicity), and limiting fragmentation and triple-Regge behaviour. This understanding involves domination of the unphysical 3 → 3 forward amplitude by the familiar Regge poles seen directly in 2 → 2 reactions. It is felt that improving data (including polarisations) must surely soon reveal Regge cuts too. A number of problems are included in the text. (U.K.)