Diffractive deep inelastic events with a large rapidity gap are analyzed by
using a Regge model for the pomeron flux and a gluonic content for the pomeron.
Contrary to the expectations, the simplest assumption for the pomeron
trajectory gives the best agreement with the data on the ratio of diffractive
to the total number of events. In this case the main properties of the model
are described by an analytic expression.Comment: 18 pages (postcript file
