Spectroscopy of eta'-nucleus bound states at GSI-SIS
  The eta' meson mass may be reduced due to partial restoration of chiral symmetry. If this is the case, an eta'-nucleus system may form a nuclear bound state. We plan to carry out a missing-mass spectroscopy with the 12C(p,d) reaction at GSI-SIS. Peak structures corresponding to such a bound state may be observed even in an inclusive measurement, if the decay width is narrow enough. 
Hiroyuki Fujioka, Kenta Itahashi, Hans Geissel, Ryugo S. Hayano,   Satoru Hirenzaki, Satoshi Itoh, Daisuke Jido, Volker Meta...
nucl-ex