Incoherent ${\pi }^0$ photoproduction from nuclei is evaluated via a multicollisional intranuclear cascade framework. In-medium modifications are taken into account, including a realistic dynamical treatment of multiple $\pi N$ and $\Delta N$ scattering processes throughout the cascade. This time-dependent analysis yields structures in the ${}^{12}\mathrm{C}{\pi }^0$ differential cross section both in the $\Delta$ region and in the photon energy range from 5 to 6 GeV, with the former in very nice agreement with recent results from Mainz Microton. For heavy nuclei, however, such structures disappear because of a more effective Fermi motion and a relatively higher final state interaction of the produced pions as they exit the nucleus. The calculation of the incoherent part of the total ${\pi }^0$ photoproduction propitiates a clean and powerful kinematical separation from competitive (electromagnetic/nuclear) production processes, which currently is a theoretical challenge for the PrimEx experiment at the Jefferson Lab.

• Received 5 November 2004

DOI:https://doi.org/10.1103/PhysRevC.71.051603