The A(K - stop ,Λd )A' reaction, a tool to observe [¯NNN] clusters

This work presents experimental results obtained from a study of the K - stop A → ΛdA' reaction, where A = 6 Li . The study concerns the distributions of the Λd invariant mass, which allows us to determine the structure of bound [K - ppn] systems in nuclei. A candidate of such clusters is identified in the present measurement, and its mass (binding energy), decay width and yield are reported. The experiment was performed at the DAΦ NE φ -facility (LNF) by using the FINUDA spectrometer. The study depended on the capability of FINUDA to reconstruct the traces of all the particles involved in the decay of the nuclear cluster.