2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/198526The contribution to diffraction dissociation of virtual photons due to quasi-elastic scattering of the $q$-$\bar q$ component is calculated in the framework of the QCD dipole picture. Both longitudinal and transverse components of the cross-section are given. It is shown that, at fixed mass of the diffractively produced system, quantum mechanical interference plays an important r\^ ole. Phenomenological consequences are discussed.latex + now: 4 encapsulated poscript figuresHigh Energy Physics - Phenomenologytext