Quantum chromodynamics

The general outline is following. QCD is introduced first as a classical, gauge-invariant, Lagrangian; general properties following from quantization and renormalization are then discussed, in particular those of dimensional transmutation and of asymptotic freedom. The remaining discussion concerns QCD predictions and splits naturally into two parts: the short-distance regime, in which suitably defined experimental quantities can be estimated as if quarks (and gluons) were free particles, and the large-distance (low momentum transfer) regime, in which, in spite of the present inability to compute, one can also argue (on the basis of several nonperturbative schemes) that QCD has a lot to do with the intricate world of hadronic phenomena. (orig./HSI)