Abstract
In a calculation of rotated matrix elements with angular momentum projection, the generalized Wick's theorem may encounter a practical problem of combinatorial complexity when the configurations have more than four quasiparticles (qp's). The problem can be solved by employing the Pfaffian algorithm generally applicable to calculations of matrix elements for Hartree-Fock-Bogoliubov states with any number of qp's. This breakthrough in many-body techniques enables studies of high-spin states in a shell-model framework. As the first application of the Pfaffian algorithm, the configuration space of the projected shell model is expanded to include 6-qp states for both positive and negative parities. Taking as an example, we show that 6-qp states become the main configuration of the yrast band beyond spin , which explains the observed third back-bending in moment of inertia. Structures of multi-qp high- isomers in are analyzed as another example.
- Received 28 April 2014
- Revised 27 June 2014
DOI:https://doi.org/10.1103/PhysRevC.90.011303
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