Spectroscopy of Heavy Lithium Isotopes 10-12Li in Stopped Pion Absorption Reactions on the 14C Target

The experimental search for the production of heavy lithium isotopes 10-12Li was carried out in the stopped π--mesons absorption reactions on the radioactive target 14C. Study of 10Li has been performed in the missing mass spectra in 14С(π-, pt)X and 14С(π-, dd)X reactions. Three excited states of 10Li were identified, thus, the broad state with a resonance energy Er = 6.1 ± 0.1 MeV has the highest excitation energy, compared with the previously observed levels. The resonance parameters of three low-lying excited states of 11Li were determined in the 14С(π-, pd)X reaction. In the 14С(π-, pp)X reaction evidence for a 12Li excited state Er = 4.0 ± 0.2 MeV and Γ = 1.1 ± 0.2 MeV has been found.