{"title":"配对强度对核结构的影响以及映射相互作用玻色子模型中的双β衰变预测","authors":"K. Nomura","doi":"10.1103/physrevc.110.024304","DOIUrl":null,"url":null,"abstract":"The low-energy nuclear structure and two-neutrino double-<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>β</mi></math> (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>ν</mi><mi>β</mi><mi>β</mi></mrow></math>) decay are studied within the interacting boson model (IBM) that is based on the nuclear energy density functional (EDF). The IBM Hamiltonian describing the initial and final even-even nuclei, and the interacting boson fermion-fermion Hamiltonian producing the intermediate states of the neighboring odd-odd nuclei are determined by the microscopic inputs provided by the self-consistent mean-field (SCMF) calculations employing a relativistic EDF and a separable pairing force. Sensitivities of the low-lying structure and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>ν</mi><mi>β</mi><mi>β</mi></mrow></math>-decay properties to the pairing strength are specifically analyzed. It is shown that the SCMF calculations with decreased and increased pairing strengths lead to quadrupole-quadrupole interaction strengths in the IBM that are, respectively, significantly enhanced and reduced in magnitude. When the increased pairing is adopted, in particular, the energy levels of the excited <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mn>0</mn><mo>+</mo></msup></math> states are lowered, and the predicted <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>2</mn><mi>ν</mi><mi>β</mi><mi>β</mi></mrow></math>-decay nuclear matrix elements (NMEs) increase in magnitude systematically. The mapped IBM employing the increased pairing force generates effective NMEs and half-lives that are in a reasonable agreement with the experimental data for the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mmultiscripts><mi>Ge</mi><mprescripts></mprescripts><none></none><mn>76</mn></mmultiscripts><mo>→</mo><mmultiscripts><mi>Se</mi><mprescripts></mprescripts><none></none><mn>76</mn></mmultiscripts></mrow><mo>,</mo><mo> </mo><mrow><mmultiscripts><mi>Se</mi><mprescripts></mprescripts><none></none><mn>82</mn></mmultiscripts><mo>→</mo><mmultiscripts><mi>Kr</mi><mprescripts></mprescripts><none></none><mn>82</mn></mmultiscripts></mrow></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mmultiscripts><mi>Mo</mi><mprescripts></mprescripts><none></none><mn>100</mn></mmultiscripts><mo>→</mo><mmultiscripts><mi>Ru</mi><mprescripts></mprescripts><none></none><mn>100</mn></mmultiscripts></mrow></math> decays in particular, whereas the calculation with the standard pairing strength is adequate to provide an overall good description of the effective NMEs in agreement with data.","PeriodicalId":20122,"journal":{"name":"Physical Review C","volume":"22 1","pages":""},"PeriodicalIF":3.1000,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effects of pairing strength on the nuclear structure and double-β decay predictions within the mapped interacting boson model\",\"authors\":\"K. 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Sensitivities of the low-lying structure and <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>2</mn><mi>ν</mi><mi>β</mi><mi>β</mi></mrow></math>-decay properties to the pairing strength are specifically analyzed. It is shown that the SCMF calculations with decreased and increased pairing strengths lead to quadrupole-quadrupole interaction strengths in the IBM that are, respectively, significantly enhanced and reduced in magnitude. When the increased pairing is adopted, in particular, the energy levels of the excited <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msup><mn>0</mn><mo>+</mo></msup></math> states are lowered, and the predicted <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mn>2</mn><mi>ν</mi><mi>β</mi><mi>β</mi></mrow></math>-decay nuclear matrix elements (NMEs) increase in magnitude systematically. The mapped IBM employing the increased pairing force generates effective NMEs and half-lives that are in a reasonable agreement with the experimental data for the <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mmultiscripts><mi>Ge</mi><mprescripts></mprescripts><none></none><mn>76</mn></mmultiscripts><mo>→</mo><mmultiscripts><mi>Se</mi><mprescripts></mprescripts><none></none><mn>76</mn></mmultiscripts></mrow><mo>,</mo><mo> </mo><mrow><mmultiscripts><mi>Se</mi><mprescripts></mprescripts><none></none><mn>82</mn></mmultiscripts><mo>→</mo><mmultiscripts><mi>Kr</mi><mprescripts></mprescripts><none></none><mn>82</mn></mmultiscripts></mrow></math>, and <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><mmultiscripts><mi>Mo</mi><mprescripts></mprescripts><none></none><mn>100</mn></mmultiscripts><mo>→</mo><mmultiscripts><mi>Ru</mi><mprescripts></mprescripts><none></none><mn>100</mn></mmultiscripts></mrow></math> decays in particular, whereas the calculation with the standard pairing strength is adequate to provide an overall good description of the effective NMEs in agreement with data.\",\"PeriodicalId\":20122,\"journal\":{\"name\":\"Physical Review C\",\"volume\":\"22 1\",\"pages\":\"\"},\"PeriodicalIF\":3.1000,\"publicationDate\":\"2024-08-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physical Review C\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1103/physrevc.110.024304\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"Physics and Astronomy\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review C","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physrevc.110.024304","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
摘要
在基于核能量密度函数(EDF)的相互作用玻色子模型(IBM)中研究了低能核结构和双中微子双β(2νββ)衰变。描述初始和最终偶-偶核的 IBM 哈密顿方程,以及产生邻近奇-偶核中间状态的相互作用玻色子-费米子哈密顿方程,都是由采用相对论能量密度函数和可分离配对力的自洽均场计算所提供的微观输入决定的。具体分析了低洼结构和 2νββ 衰变特性对配对力的敏感性。结果表明,配对强度减小和增大的 SCMF 计算导致 IBM 中的四极-四极相互作用强度分别显著增强和减小。特别是当采用增加配对时,激发的 0+ 态能级降低,预测的 2νββ 衰变核矩阵元素(NMEs)的量级系统地增加。采用增加配对力的映射 IBM 产生的有效核矩阵元素和半衰期与 Ge76→Se76、Se82→Kr82 和 Mo100→Ru100 衰变的实验数据相当吻合,而采用标准配对力的计算则足以提供与数据吻合的有效核矩阵元素的总体良好描述。
Effects of pairing strength on the nuclear structure and double-β decay predictions within the mapped interacting boson model
The low-energy nuclear structure and two-neutrino double- () decay are studied within the interacting boson model (IBM) that is based on the nuclear energy density functional (EDF). The IBM Hamiltonian describing the initial and final even-even nuclei, and the interacting boson fermion-fermion Hamiltonian producing the intermediate states of the neighboring odd-odd nuclei are determined by the microscopic inputs provided by the self-consistent mean-field (SCMF) calculations employing a relativistic EDF and a separable pairing force. Sensitivities of the low-lying structure and -decay properties to the pairing strength are specifically analyzed. It is shown that the SCMF calculations with decreased and increased pairing strengths lead to quadrupole-quadrupole interaction strengths in the IBM that are, respectively, significantly enhanced and reduced in magnitude. When the increased pairing is adopted, in particular, the energy levels of the excited states are lowered, and the predicted -decay nuclear matrix elements (NMEs) increase in magnitude systematically. The mapped IBM employing the increased pairing force generates effective NMEs and half-lives that are in a reasonable agreement with the experimental data for the , and decays in particular, whereas the calculation with the standard pairing strength is adequate to provide an overall good description of the effective NMEs in agreement with data.
期刊介绍:
Physical Review C (PRC) is a leading journal in theoretical and experimental nuclear physics, publishing more than two-thirds of the research literature in the field.
PRC covers experimental and theoretical results in all aspects of nuclear physics, including:
Nucleon-nucleon interaction, few-body systems
Nuclear structure
Nuclear reactions
Relativistic nuclear collisions
Hadronic physics and QCD
Electroweak interaction, symmetries
Nuclear astrophysics