Spectroscopy of $eta$-nucleus bound states at GSI and FAIR --- very preliminary results and future prospects ---

The possible existence of eta-nucleus bound states has been put forward through theoretical and experimental studies. It is strongly related to the eta mass at finite density, which is expected to be reduced because of the interplay between the $U_A(1)$ anomaly and partial restoration of chiral symmetry. The investigation of the C(p,d) reaction at GSI and FAIR, as well as an overview of the experimental program at GSI and future plans at FAIR are discussed.