Dilute multi-α cluster states in nuclei -: art. no. 024309

Dilute multi-alpha cluster condensed states with spherical and axially deformed shapes are studied with the Gross-Pitaevskii equation and Hill-Wheeler equation, where the alpha cluster is treated as a structureless boson. Applications to self-conjugate 4N nuclei show that the dilute Nalpha states of C-12 to Ca-40 with J(pi)=0(+) appear in the energy region from threshold up to about 20 MeV, and the critical number of alpha bosons that the dilute Nalpha system can sustain as a self-bound nucleus is estimated roughly to be N(cr)similar to10. We discuss the characteristics of the dilute Nalpha states with emphasis on the N dependence of their energies and rms radii.