Photoproduction of Mesons off Light Nuclei -- the Search for η -Mesic Nuclei

Photoproduction of \eta mesons off light nuclei (d, 3He, 7Li) has been measured at the tagged photon beam of the Mainz MAMI accelerator with the combined Crystal Ball/TAPS detection system. Special attention was given to the threshold behavior of the reactions in view of possible indications for the formation of (quasi-) bound \eta -nucleus states, so-called \eta -mesic nuclei. A very strong threshold enhancement of coherent \eta photoproduction off 3He was found and coherent \eta photoproduction off 7Li was observed for the first time. Preliminary results will be discussed.