{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2022,4,1]],"date-time":"2022-04-01T14:58:25Z","timestamp":1648825105101},"reference-count":14,"publisher":"World Scientific Pub Co Pte Lt","issue":"05","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mod. Phys. E"],"published-print":{"date-parts":[[1999,10]]},"abstract":"<jats:p> An exact eigenstate of the Lipkin-model Hamiltonian has a parity-symmetry. The resonating Hartree-Fock (Res-HF) ground-state wave function however breaks the parity-symmetry. To restore the parity-symmetry, we develop a parity-projected (P-P) Res-HF approximation to the Lipkin model. The P-P Res-HF wave function is superposed by two P-P Slater determinants. Self-consistent calculation is carried out so as to optimize the P-P Res-HF energy functional. A Res-HF ground state with definite parity brings us the ground-state energy much nearer to the exact one than that the Res-HF and explains most of the ground-state correlation energy. We also show behaviour of P-P Res-HF orbital energies and mixing coefficients calculated by the P-P Res-HF approximation and compare them with those calculated by the parity-unprojected Res-HF approximation. From this comparison, we find very interesting relations between them which have never been seen in the parity-unprojected Res-HF calculation. <\/jats:p>","DOI":"10.1142\/s0218301399000306","type":"journal-article","created":{"date-parts":[[2003,5,7]],"date-time":"2003-05-07T08:18:55Z","timestamp":1052295535000},"page":"443-460","source":"Crossref","is-referenced-by-count":2,"title":["PARITY-PROJECTED RESONATING HARTREE-FOCK APPROXIMATION TO THE LIPKIN MODEL"],"prefix":"10.1142","volume":"08","author":[{"given":"SEIYA","family":"NISHIYAMA","sequence":"first","affiliation":[{"name":"Centro de F\u00edsica Te\u00f3rica, Universidade de Coimbra, 3000 - Coimbra, Portugal"},{"name":"Department of Physics, Kochi University, Kochi 780-8520, Japan"}]},{"given":"MORIYOSHI","family":"IDO","sequence":"additional","affiliation":[{"name":"Centro de F\u00edsica Te\u00f3rica, Universidade de Coimbra, 3000 - Coimbra, Portugal"},{"name":"Department of Physics, Kochi University, Kochi 780-8520, Japan"}]},{"given":"KAZUHIRO","family":"ISHIDA","sequence":"additional","affiliation":[{"name":"Centro de F\u00edsica Te\u00f3rica, Universidade de Coimbra, 3000 - Coimbra, Portugal"},{"name":"Department of Physics, Kochi University, Kochi 780-8520, Japan"}]}],"member":"219","published-online":{"date-parts":[[2012,1,25]]},"reference":[{"key":"p_1","doi-asserted-by":"publisher","DOI":"10.1143\/PTP.80.417"},{"key":"p_2","doi-asserted-by":"publisher","DOI":"10.1143\/PTP.81.342"},{"key":"p_3","doi-asserted-by":"publisher","DOI":"10.1143\/PTP.85.1211"},{"key":"p_4","doi-asserted-by":"publisher","DOI":"10.1143\/PTP.86.371"},{"key":"p_5","doi-asserted-by":"publisher","DOI":"10.1016\/0029-5582(65)90862-X"},{"key":"p_6","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/0375-9474(94)90248-8","volume":"576","author":"Nishiyama S.","year":"1994","journal-title":"Nucl. Phys."},{"key":"p_7","doi-asserted-by":"publisher","DOI":"10.1016\/0375-9474(95)00460-2"},{"key":"p_8","doi-asserted-by":"publisher","DOI":"10.1016\/0029-5582(66)90540-2"},{"key":"p_9","doi-asserted-by":"publisher","DOI":"10.1016\/0029-5582(60)90048-1"},{"key":"p_10","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRev.175.1293"},{"key":"p_11","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1088\/0370-1298\/70\/5\/309","volume":"70","author":"Peierls R. E.","year":"1967","journal-title":"Proc. Phys. Soc."},{"key":"p_13","doi-asserted-by":"publisher","DOI":"10.1088\/0954-3899\/18\/2\/013"},{"key":"p_15","first-page":"129","volume":"511","author":"Gambhir Y. K.","year":"1990","journal-title":"Y.)"},{"key":"p_16","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.77.3963"}],"container-title":["International Journal of Modern Physics E"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.worldscientific.com\/doi\/pdf\/10.1142\/S0218301399000306","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,8,7]],"date-time":"2019-08-07T14:33:22Z","timestamp":1565188402000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.worldscientific.com\/doi\/abs\/10.1142\/S0218301399000306"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,10]]},"references-count":14,"journal-issue":{"issue":"05","published-online":{"date-parts":[[2012,1,25]]},"published-print":{"date-parts":[[1999,10]]}},"alternative-id":["10.1142\/S0218301399000306"],"URL":"https:\/\/doi.org\/10.1142\/s0218301399000306","relation":{},"ISSN":["0218-3013","1793-6608"],"issn-type":[{"value":"0218-3013","type":"print"},{"value":"1793-6608","type":"electronic"}],"subject":[],"published":{"date-parts":[[1999,10]]}}}