Investigations of three-, four-, and five-particle decay channels of levels in light nuclei created using aC9beam

The interactions of an E/A=70-MeV {sup 9}C beam with a Be target was used to populate levels in Be, B, and C isotopes, which undergo decay into many-particle exit channels. The decay products were detected in the HiRA array and the level energies were identified from their invariant mass. Correlations between the decay products were examined to deduce the nature of the decays, specifically to what extent all the fragments were created in one prompt step or whether the disintegration proceeded in a sequential fashion through long-lived intermediate states. In the latter case, information on the spin of the level was also obtained. Of particular interest is the five-body decay of the {sup 8}C ground state, which was found to disintegrate in two steps of two-proton decay passing through the {sup 6}Be{sub g.s.} intermediate state. The isobaric analog of {sup 8}C{sub g.s.} in {sup 8}B was also found to undergo two-proton decay to the isobaric analog of {sup 6}Be{sub g.s.} in {sup 6}Li. A 9.69-MeV state in {sup 10}C was found to undergo prompt four-body decay to the 2p + 2{alpha} exit channel. The two protons were found to have a strong enhancement in the diproton region and the relativemore » energies of all four p-{alpha} pairs were consistent with the {sup 5}Li{sub g.s.} resonance.« less