Spectroscopy of 7Li in stopped pion absorption reactions

The structure of excited levels in the 7Li isotope is studied via inclusive and correlation measurements in the stopped π− meson absorption reactions 10B(π−, t)X and 12C(π−, dt)X, respectively. The experiment is conducted using a low-energy pion beam at the LAMPF meson factory. Analysis of the missing mass spectra reveals 7Li states with the resonance parameters (E x , Γ) (4.7, 0.1), (6.6, 0.9), (7.3, 0.1), (9.1, 2.8), and (9.6, 0.4) MeV. A highly excited state with E x ≈ 11.2 MeV (i.e., an isobar analog of 7He) is observed in the 10B(π−,t)X reaction. An excited state with E x = 10.3 ± 0.1 MeV and γ = 1.8 ± 0.4 Mev is observed for the first time in the 12C(π−,dt)X reaction.