Searching for exotic cluster structure in the absorption of pions by the 11B nucleus

Correlation measurements of the reaction of stopped pion absorption 11B(π−, tt)X are made with a semiconductor double-arm charged particle spectrometer on a low-energy pion beam at the LAMPF meson factory. Analysis of a two-dimensional Dalitz plot and the momentum distribution of the residual nucleus allows us to identify the absorption of pions in a 6Li intranuclear cluster and demonstrate the configuration 6Li + 5Heg.s is present in the 11B nucleus.