Cluster Structure of the Ground and Excited States of ⁹Be and ¹⁰B Nuclei

Abstract

Reactions of quasielastic (p, px), (e, ex) knockout and reactions of (γ, x) photodisintegration show that particles x—deuterons, tritons, α-particles and nucleons—escape with a comparable probability out of light nuclei. The significant values of spectroscopic S-factors in these channels are evidence of this. This situation is well interpreted by the wave functions of multiparticle shell model which allows considering from the unified positions both cluster and nucleonic degrees of freedom. The situation in ⁹Be and ¹⁰B nuclei is of peculiar interest. In these nuclei from analysis of symmetry of orbital part of wave functions of states at high energies it was suggested for instance in ⁹Be nucleus to search three-cluster αtd-states in reactions with ^6,7Li ions on the same target nuclei. Our calculations showed that in excitation spectra of ⁹Be nucleus there are three-cluster αtd-states situating in range of both 17–19 and 10–11 MeV. These states have large S-factors in triton, deuteron (and α-particle) channels simultaneously, moreover the last ones appear exactly due to [441] states. Similar conclusions were also obtained for ¹⁰B nucleus where three-particle ατt-levels are connected not only to states with Young [433] scheme, but to [442].