DEEP-INELASTIC ELECTRON-POMERON SCATTERING AT HERA

The idea that the pomeron has partonic structure similar to any other hadron has been given strong support by recent measurements of the dif fractive structure function at HERA. We present a detailed theoretical analysis of the diffractive structure function under the assumption t hat the diffractive cross section can be factorized into a pomeron emi ssion factor and the deep inelastic scattering cross section of the po meron. We pay particular attention to the kinematic correlations impli ed by this picture, and suggest the measurement of an angular correlat ion which should provide a first test of the whole picture. We also pr esent two simple phenomenological models for the quark and gluon struc ture of the pomeron, which are consistent with various theoretical ide as and which give equally good fits to recent measurements by the H1 c ollaboration, when combined with the pomeron emission factor of Donnac hie and Landshoff. We predict that a large fraction of diffractive dee p inelastic events will contain charm, and discuss how improved data w ill be able to distinguish the models.