Method to circumvent the neutron gas problem in the BCS treatment for nuclei far from stability
| Autor: | Ono, Toshiya, Shimizu, Yoshifumi R., Tajima, Naoki, Takahara, Satoshi |
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| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | Phys.Rev.C82:034310,2010 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevC.82.034310 |
| Popis: | Extending the Kruppa's prescription for the continuum level density, we have recently improved the BCS method with seniority-type pairing force in such a way that the effects of discretized unbound states are properly taken into account for finite depth single-particle potentials. In this paper, it is further shown, by employing the Woods-Saxon potential, that the calculation of spatial observables like nuclear radius converges as increasing the basis size in the harmonic oscillator expansion. Namely the disastrous problem of a "particle gas" surrounding nucleus in the BCS treatment can be circumvented. In spite of its simplicity, the new treatment gives similar results to those by more elaborate Hartree-Fock-Bogoliubov calculations; e.g., it even mimics the pairing anti-halo effect. The obtained results as well as the reason of convergence in the new method are investigated by a variant of the Thomas-Fermi approximation within the limited phase space which corresponds to the harmonic oscillator basis truncation. Comment: 23 pages, 8 figures |
| Databáze: | arXiv |
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