Spectroscopy of the lithium isotopes ^7-9Li

Abstract.

Experimental search for highly excited states of the lithium isotopes ^7-9Li was carried out in the stopped $\pi^{-}$-meson absorption reactions. Several states were found for the first time. Evidence of the existence of the ⁸Li level with $E_{x}=11.2\pm 0.2$ MeV, $13.5\pm 0.1$ MeV and $17.5\pm 0.3$ MeV was found in the ¹²C($\pi^{-}, dd$)X reaction. In the ¹¹B($\pi^{-}, d$)X reaction the level of ⁹Li with $E_{x}=9.1\pm 0.1$ MeV, which lies above the threshold ⁹Li^* $\rightarrow$ ⁶He $+t$, was observed. An indication for the formation of the ⁹Li state with $E_{x}\approx 10.5$ MeV was obtained in the ¹²C($\pi^{-},p d$)X reaction.