Coherent π0 photoproduction off 7Li

Charge and matter densities are among the most fundamental properties of atomic nuclei. Nuclear charge distributions have been intensively studied (elastic electron scattering, muonic atoms). However, this techniques do not allow the extraction of the nuclear mass distributions. One possible alternative is the use of the coherent π0 photoproduction, which is sensitive to the distribution of the nucleons. First results on carbon, calcium, niobium, and lead have been recently published. The present work aims to extend this study to light nuclei. The coherent photoproduction of π0 off 7Li has been studied at the MAMI accelerator for photon energies throughout the Δ-resonance up to 830 MeV. The experiment used the Glasgow photon tagging device and the combined Crystal Ball/TAPS electromagnetic calorimeter. With the availability of 4π solid angle coverage provided by CB/TAPS, high quality and precise data have been obtained. Preliminary results of the angular distributions and momentum transfer dependence of the coherent cross section are discussed in view of the extraction of the nuclear mass form factor in plane wave approximation.