Glauber multiple scattering theory for the photoproduction of vector mesons off nuclei and the role of the coherence length

The integrated cross section for the incoherent photoproduction of vector mesons on nuclei γ∗A → VX, X ≠ A, is calculated within Glauber theory and as a function of the photon energy. The inverse of the longitudinal momentum transfer is called coherence length lc and depends on the virtuality and the energy of the photon. Nuclear transmission factors strongly depend on lcRa (Ra is the nuclear radius) and this effect may interfere with the search for color transparency effects.