1996 Fiscal Year Annual Research Report

元素の起源と宇宙の進化

Research Project

Project/Area Number	05243103
Research Institution	The University of Tokyo
Principal Investigator	野村亨東京大学, 原子核研究所, 教授 (60087393)
Co-Investigator(Kenkyū-buntansha)	高塚龍之岩手大学, 人文社会科学部, 教授 (50043427) 土岐博大阪大学, 核物理研究センター, 教授 (70163962) 本林透立教大学, 理学部, 教授 (20116114) 加藤静吾山形大学, 理学部, 教授 (70013422) 久保野茂東京大学, 原子核研究所, 助手 (20126048)
Keywords	天体核反応 / 超新星爆発 / 中性子過剰核物質 / 太陽ニュートリノ / クーロン分解 / 状態方程式 / 不安定核ビーム / 中性子星
Research Abstract	本研究の目的は、短寿命核の天体核反応率の測定と、超新星爆発機構及び中性子過剰核物質等の理論的な考察・計算等を通じて、元素の起源と宇宙の進化を研究することである。ア)実験研究クローン分解法と間接法による短寿命核の天体核反応率の測定を集中的に実施し、太陽ニュートリノ問題と関連する^7Be(p,γ)^8B反応率の再測定・解析を実施するとともに、高温天体における水素の爆発的核燃焼率(RP過程)に関わる多数の反応率を決定した。前者においては直接測定法による実験値のうち比較的小さな値と合致する高精度の結果を得ており、現在、論文にまとめている。後者においては、^<22>Na→^<23>Mg→^<24>Al→^<25>Siの流れに関して星の温度と密度の条件を確立することに成功した。また、RP過程でどこまで重い元素ができるかを決める鍵である^<59>Cu(p,γ)^<60>Cu反応の研究を実施した。また、不安定核の直接反応では、RP過程の入口に相当する^<19>Nc(p,γ)^<20>Na反応を目標にして不安定核ビームの開発を進め、毎秒5x10^8個のビームを得ることに成功した。イ)理論的研究超新星爆発機構と誕生後間もない中性子星の進化を解明するため、i)有限温度の中性子過剰核物質である超新星物質の状態方程式(EOS)の探究と、ii)星の自転とその効果による流体的爆発現象の解明を前年度に継続して行った。前者においては、相対論的平均場法と有限温度ハートリーフォック法からのアプローチを採用し、各々、不安定核の基礎的性質をよく再現するパラメターの決定と高密度超新星物質のEOSと熱力学的諸量の導出し、論文として発表した。後者においては、超新星コア内の対流効果を調べ、爆発が起こるためにはある適当な角運動量が必要で、軸方向に放出されるニュートリノによりジェット爆発が誘起される可能性があることを指摘できた。これらの研究成果は、約50篇の論文ないし解説として公表した。

Research Products
(25 results)

All Other

All Publications (25 results)

[Publications] T.Nomura: "Possible New Approaches to Superheavy Elements-(HI,αχn)Reaction and the Neutron-Rich Beam" Hyperfine Interactions. 103. 33-42 (1996)
[Publications] T.Nomura: "Comments on Superheavy Element Production with Neutron-Rich Beams" Proceedings of the French-Japanese Colloquium on Frontier and Perspective of Nuclear Science. (1996)
[Publications] S.C.Jeong et al.: "Beam-Bunching in an ECR Ion Source by the Pulsed Gating-Potential Method" Nucl.Instr.Meth.B114. 154-163 (1996)
[Publications] A.Yoshida et al.: "Fusion and Breakup at the Barrier with ^<11>Be" Physics Letters. B389. 457-462 (1996)
[Publications] C.Signorini: "Fusion and Breakup at the Barrier with Unstable Nuclei" Proceedings of the 4th International Conference on Radioactive Nuclear Beams. (1996)
[Publications] T.Nomura: "Heavy-Element Research at RIKEN" Proceedings of International Conferece on Exotic Nuclei and Atomic Masses,. 363-372 (1996)
[Publications] Y.H.Pu et al.: "New α-Decaying Neutron-Deficient Isotope ^<196>Rn" Zeitschrift fur Physik. A357. 1-2 (1997)
[Publications] G.Raimann et al.: "Levels in ^<17>C above the ^<16>C+Neutron Thershold" Phys.Rev.C53. 453-458 (1996)
[Publications] T.Yamaya et al.: "α-Cluster States above the Thershold in ^<44>Ti" Phys.Rev.C53. 131-136 (1996)
[Publications] S.Kubono: "Nuclear Astrophysics with Radioactive Nuclear Beams" Prog.Theor.Phys.96. 275-306 (1996)
[Publications] N.Iwasa et al.: "Study of the ^7Be(p,γ)^8B Reaction with Coulomb Dissociation Method" J.Phys.Soc.Jpn.65. 1256-1263 (1996)
[Publications] T.Kikuchi et al.: "Experimental Dctermination of the E2 Component in the Coulomb Dissociation of ^8B" Phys.Lett.B391. 261-266 (1997)
[Publications] T.Totani et al.: "Spectrum of the Supernova Relic Neutrino Background and Evolution of Galaxies" Astropys.J.460. 303-312 (1996)
[Publications] T.Totani et al.: "Effects of Neutrino Oscillation on the Supernova Relic Neutrino Background" Int.J.Mod.Phys.D5. 519-527 (1996)
[Publications] T.Totani et al.: "Resonant Spin-Flavor Conversion of Supernova Neutrinos and Deformation of the Electron Antineutrino Spectrum" Physical Review. D54. 5975-5992 (1996)
[Publications] K.Ikumi et al.: "Anisotropy in Kaluza-Klein Quantum Cosmology" Nucl.Phys.B. (in press). (1997)
[Publications] K.Iida et al.: "Spin-Down of Neutron Stars and Compositional Transitions in the Cold Crustal Matter" Astrophysical Journal. (in press). (1997)
[Publications] K.Sato et al.: "Gravitational Collapse of Rotating Stellar Cores and Supernova" Nucl.Phys.A606. 118-136 (1996)
[Publications] A.Hosaka et al.: "Chiral Bag Model for the Nucleon" Phys.Rep.277. 65-188 (1996)
[Publications] H.Ichie et al.: "Multi-Flux-Tube System in the Dual Ginzburg-Landau Theory" Phys.Rev.D54. 3382-3388 (1996)
[Publications] K.Suzuki et al.: "Heavy Quarkonium in the Dual Ginzburg-Landau Theory of QCD" Int.J.of Mod.Phys.A11. 2677-2688 (1996)
[Publications] S.Sasaki et al.: "Role of Dual Higgs Mechanism in Chiral Phase Transition at Finite Temperature" Phys.Lett.B387. 145-150 (1996)
[Publications] H.Toki et al.: "Theoretical Response to the Discovery of Deeply Bound Pionic States in ^<208>Pb(d.^3Hc)Reactions" Z.Phys.A. (in press).
[Publications] T.Takatsuka: "Nucleon Superfluidity in Neutron Stars Core with Direct URCA Cooling" Progress of Theoretical Physics. 97. No.2- (1997)
[Publications] T.Takatsuka: "Effects of Charged-Pion Condensation on Neutron ^3P_2 Superfluidty" Progress of Theoretical Physics. 97. No.2- (1997)

1996 Fiscal Year Annual Research Report

元素の起源と宇宙の進化

Principal Investigator

野村 亨 東京大学, 原子核研究所, 教授 (60087393)

Research Products

[Publications] T.Nomura: "Possible New Approaches to Superheavy Elements-(HI,αχn)Reaction and the Neutron-Rich Beam" Hyperfine Interactions. 103. 33-42 (1996)

[Publications] T.Nomura: "Comments on Superheavy Element Production with Neutron-Rich Beams" Proceedings of the French-Japanese Colloquium on Frontier and Perspective of Nuclear Science. (1996)

[Publications] S.C.Jeong et al.: "Beam-Bunching in an ECR Ion Source by the Pulsed Gating-Potential Method" Nucl.Instr.Meth.B114. 154-163 (1996)

[Publications] A.Yoshida et al.: "Fusion and Breakup at the Barrier with ^<11>Be" Physics Letters. B389. 457-462 (1996)

[Publications] C.Signorini: "Fusion and Breakup at the Barrier with Unstable Nuclei" Proceedings of the 4th International Conference on Radioactive Nuclear Beams. (1996)

[Publications] T.Nomura: "Heavy-Element Research at RIKEN" Proceedings of International Conferece on Exotic Nuclei and Atomic Masses,. 363-372 (1996)

[Publications] Y.H.Pu et al.: "New α-Decaying Neutron-Deficient Isotope ^<196>Rn" Zeitschrift fur Physik. A357. 1-2 (1997)

[Publications] G.Raimann et al.: "Levels in ^<17>C above the ^<16>C+Neutron Thershold" Phys.Rev.C53. 453-458 (1996)

[Publications] T.Yamaya et al.: "α-Cluster States above the Thershold in ^<44>Ti" Phys.Rev.C53. 131-136 (1996)

[Publications] S.Kubono: "Nuclear Astrophysics with Radioactive Nuclear Beams" Prog.Theor.Phys.96. 275-306 (1996)

[Publications] N.Iwasa et al.: "Study of the ^7Be(p,γ)^8B Reaction with Coulomb Dissociation Method" J.Phys.Soc.Jpn.65. 1256-1263 (1996)

[Publications] T.Kikuchi et al.: "Experimental Dctermination of the E2 Component in the Coulomb Dissociation of ^8B" Phys.Lett.B391. 261-266 (1997)

[Publications] T.Totani et al.: "Spectrum of the Supernova Relic Neutrino Background and Evolution of Galaxies" Astropys.J.460. 303-312 (1996)

[Publications] T.Totani et al.: "Effects of Neutrino Oscillation on the Supernova Relic Neutrino Background" Int.J.Mod.Phys.D5. 519-527 (1996)

[Publications] T.Totani et al.: "Resonant Spin-Flavor Conversion of Supernova Neutrinos and Deformation of the Electron Antineutrino Spectrum" Physical Review. D54. 5975-5992 (1996)

[Publications] K.Ikumi et al.: "Anisotropy in Kaluza-Klein Quantum Cosmology" Nucl.Phys.B. (in press). (1997)

[Publications] K.Iida et al.: "Spin-Down of Neutron Stars and Compositional Transitions in the Cold Crustal Matter" Astrophysical Journal. (in press). (1997)

[Publications] K.Sato et al.: "Gravitational Collapse of Rotating Stellar Cores and Supernova" Nucl.Phys.A606. 118-136 (1996)

[Publications] A.Hosaka et al.: "Chiral Bag Model for the Nucleon" Phys.Rep.277. 65-188 (1996)

[Publications] H.Ichie et al.: "Multi-Flux-Tube System in the Dual Ginzburg-Landau Theory" Phys.Rev.D54. 3382-3388 (1996)

[Publications] K.Suzuki et al.: "Heavy Quarkonium in the Dual Ginzburg-Landau Theory of QCD" Int.J.of Mod.Phys.A11. 2677-2688 (1996)

[Publications] S.Sasaki et al.: "Role of Dual Higgs Mechanism in Chiral Phase Transition at Finite Temperature" Phys.Lett.B387. 145-150 (1996)

[Publications] H.Toki et al.: "Theoretical Response to the Discovery of Deeply Bound Pionic States in ^<208>Pb(d.^3Hc)Reactions" Z.Phys.A. (in press).

[Publications] T.Takatsuka: "Nucleon Superfluidity in Neutron Stars Core with Direct URCA Cooling" Progress of Theoretical Physics. 97. No.2- (1997)

[Publications] T.Takatsuka: "Effects of Charged-Pion Condensation on Neutron ^3P_2 Superfluidty" Progress of Theoretical Physics. 97. No.2- (1997)

野村亨東京大学, 原子核研究所, 教授 (60087393)