Hard and soft contributions in diffraction: a closer look

Disentangle the hard and soft dynamics in diffractive DIS is one of the mai n open questions of the strong interactions. We propose the study of the lo garithmic slope in Q(2) of the diffractive structure function as a potentia l observable to discriminate between the Regge and the QCD-bas:ed approache s. Our results indicate that a future experimental analyzes could evidentia te the leading dynamics at ep diffractive processes in the HERA kinematical regime. (C) 2001 Published by Elsevier Science B.V.