Cluster model investigation of 223Ac

We model the odd-proton nucleus Ac-223 as a Pb-208+C-14+p system. The odd proton occupies 0h(9/2). 1f(7/2), and 0i(13/2) states with energies taken from the known spectrum of Bi-209, while the C-14 cluster occupies 0(+), 2(+) 4(+),..., and 1(-), 3(-), 5(-),.., states, relative to Pb-208, whose energies are taken from the known levels of Ra-222. The C-14-p interaction mixes together the various combinations of proton and C-14 orbital motion states coupled to total angular momentum I. The Pauli principle is satisfied by excluding the odd proton from orbitals above the Pb-208 Fermi surface already occupied by protons in the C-14 cluster. We predict low-lying parity doublet bands with K-pi values 5/2(+/-) and 3/2(+/-), in agreement with observation. [S0556-2813(98)00311-2].