Effects of orbital occupancies and spin-orbit partners II: 0vββ decays of 76Ge, 82Se and 136Xe to first excited 0+ states

The neutrinoless double beta (0v beta beta) decays of Ge-76, Se-82 and Xe-136 to the first excited 0(+) states (0(1)(+)) in Se-76, Kr-82 and Ba-136 are studied in calculations using different sizes of the single-particle model spaces and different occupancies of the individual orbits. This is a continuation of a similar study [J. Suhonen, O. Civitarese, Effects of orbital occupancies and spin orbit partners on 0v beta beta-decay rates, Nucl. Phys. A 847 (2010) 207-232] of the 0v beta beta decays of Ge-76, Se-82, Te-128, Te-130 and Xe-136 to the ground states of Se-76, Kr-82, Xe-128, Xe-130 and Ba-136. The nuclear matrix elements and half-lives of the decays to the 0(1)(+) states are calculated by the use of the multiple-commutator model with effective, G-matrix-derived nuclear forces. Interestingly, the basic features of the ground-state and excited-state decays are found to be quite different. The half-lives of the excited-state transitions are suppressed by at least one order of magnitude relative to the ground-state transitions. (C) 2011 Elsevier B.V. All rights reserved.