Low energy onset of nuclear shadowing in photoabsorption - art. no. 031602

The early onset of nuclear shadowing in photoabsorption at low photon energ ies (greater than or similar to 1 GeV) has recently been interpreted as a p ossible signature of a decrease of the rho meson mass in nuclei. We show th at one can understand this early onset within simple Glauber theory if one takes the negative real part of the rho N scattering amplitudes into accoun t, corresponding to a higher effective mass of the rho meson in nuclear med ium.