THE SOFT POMERON AND HERA

The standard phenomenology of the soft pomeron in hadron-hadron intera ctions is recalled briefly. The model is confronted with the HERA data for the total photoproduction cross section, deep inelastic scatterin g, diffractive vector meson photoproduction and diffractive electropro duction of vector mesons. Although much of the data can be explained b y the model, there are some aspects of the HERA data which require a m ore rapid variation with energy than can be incorporated. It is argued that the perturbative (BFKL) pomeron cannot give a sufficiently large contribution to explain these observations. Possible non-perturbative solutions to this problem are indicated.