Dipole Excitation Of Alpha Clusters In Li-6 And Li-7

Dipole excitations in highly excited energy regions of He-6 and He-7 nuclei were investigated via the (Li-7,Be-7) reaction with an incident energy of 65A MeV at forward scattering angles. The resonances at Q similar or equal to -30 MeV observed commonly for both Li-6 and Li-7 targets were found to be excited via both spin-flip and spin-nonflip transitions with DeltaL = 1. Based on the observed excitation energy, width, and cross section of each resonance, the relevant resonances are inferred to be analogs of the dipole resonances of a clusters in the Li-6 and Li-7 nuclei.