Search for the 3He-eta bound state at COSY-11
  We have measured excitation function for dp -> ppp_pi- reaction near the eta production threshold. We observe an enhancement of the counting rate above the threshold which can originate from the production of the eta meson in the reaction dp -> 3He eta and its subsequent absorption on neutron in the 3He nucleus leading to creation of the p_pi- pair. 
W. Krzemien, J. Smyrski, A. Budzanowski, E. Czerwinski, R.   Czyzykiewicz, D. Gil, D. Grzonka, L. Jarczyk, B. Kamys, A. Khou...