2000 Fiscal Year Annual Research Report

ニュートリノ振動現象の研究

Research Project

Project/Area Number	12047222
Research Category	Grant-in-Aid for Scientific Research on Priority Areas (A)
Research Institution	Tokyo Metropolitan University
Principal Investigator	南方久和東京都立大学, 理学研究科, 教授 (00112475)
Co-Investigator(Kenkyū-buntansha)	荒船次郎東京大学, 宇宙線研究所, 教授 (80013415) 北澤敬章東京都立大学, 理学研究科, 助手 (20271158) 安田修東京都立大学, 理学研究科, 助手 (50183116) 柳田勉東京大学, 理学系研究所, 教授 (10125677) 福来正孝東京大学, 宇宙線研究所, 教授 (40100820)
Keywords	ニュートリノ振動 / フレーバー混合 / ニュートリノ質量 / CP非保存 / MSW効果 / 長基線ニュートリノ実験 / 超新星ニュートリノ / 不活性ニュートリノ
Research Abstract	(1)長基線ニュートリノ振動実験によるCP非保存効果の測定の問題に対して「物質汚染問題のない、しかも実験可能なパラメター領域を捜せ」という至極当たり前のしかしこれまで誰も試みなかった新しいアプローチを試みた。その結果、nu_mu→nu_eモードを使い、100MeV程度のエネルギーを持つ正反ミューニュートリノ・ビームの引き算によってCP非保存効果の測定を行うとよいことが分かった。但し、太陽ニュートリノ問題の大混合角解を仮定する必要がある。現在のK2K実験のビーム強度の2桁の改善とメガトン級水チェレンコフ検出器があればこのような実験が可能であることが分かった。 (2)3世代ニュートリノでの超新星物質中でのニュートリノフレーバー転換についての一般論を展開し、これを用いてニュートリノの質量パターンによって転換パターンが変わること、とりわけ混合行列の(1-3)要素が断熱遷移を許す範囲にあるか否かによって転換パターンが大きく変化することを指摘した。この性質を使って超新星ニュートリノの解析からニュートリノの質量パターンに対する制限を得る方法を開発した。さらにこれを使って、超新星1987Aからのニュートリノデータの解析を行い、inverted mass hierarchyと呼ばれる質量パターンがデータの特徴と符合しないことを指摘した。 (3)活動銀河核等宇宙から来る高エネルギーニュートリノを水・氷等からなる大型チェレンコフ光測定器で測定する際、測定されるニュートリノのフレーバーの比率の違いにより三世代と不活性ニュートリノを含む四世代の間のニュートリノ振動が区別できる可能性があることを示した。 (4)スーパーカミオカンデの大気ニュートリノのデータを不活性ニュートリノを含む4世代の間のニュートリノ振動の枠組で解析し、従来知られていた振動パラメーターよりも広い範囲で解が存在することを示した。

Research Products

(36 results)

All Other

All Publications (36 results)

[Publications] H.Minakata and H.Nunokawa: "Inverted Hierarchy of Neutrino Masses Disfavored by Supernova 1987A"Physics Letters B.. 504. 301-308 (2001)
[Publications] H.Hiro-Oka and H.Minakata: "Dynamical Pion Production via Parametric Resonance from Disoriented Chiral Condensate"Physical Review C. 61. 044903 (2000)
[Publications] H.Minakata and H.Nunokawa: "Measuring Leptonic CP Violation by Low Energy Neutrino Oscillation Experiments"Physics Letters B. 495. 369-377 (2000)
[Publications] A.Chodos,F.Cooper,W.Mao,H.Minakata,and A.Singh: "Two-Dimensional Model with Chiral Condensate and Cooper Pairs having QCD-like Phase Structure"Physical Review D. 61. 045011 (2000)
[Publications] 浅川正之,南方久和: "カイラル対称性の破れによるドメイン構造(解説)"日本物理学会誌. 55. 263-272 (2000)
[Publications] H.Athar,M.Jezabek and O.Yasuda: "Effects of Neutrino Mixing on High-energy Cosmic Neutrino Flux"Physical Review D. 62. 103007 (2000)
[Publications] N.Kitazawa,N.Maru and N.Okada: "R Mediation of Dynamical Supersymmetry Breaking"Physical Review D. 63. 015005 (2001)
[Publications] N.Kitazawa,N.Maru and N.Okada: "Models of Supersymmetry Breaking with Gauged U(1)(R)Symmetry"Nuclear Physics B. 586. 261-274 (2000)
[Publications] N.Kitazawa,N.Maru and N.Okada: "Dynamical Supersymmetry Breaking with Gauged U(1)(R)Symmetry"Physical Review D. 62. 077701 (2000)
[Publications] N.Kitazawa: "Determination of the Dynamically Generated Yukawa Coupling in Supersymmetric QCD"Physical Review D. 61. 056008 (2000)
[Publications] J.Arafune,T.Yoshida,S,Nakamura,K.Ogure: "Experimental bounds on masses and fluxes of nontopological solitons"Physical Review. D62(10). 105013-1-105013-11 (2000)
[Publications] CP-PACS collaboration (M,Fukugita et al.): "Phase structure and critical temperature of two flavor CD with renormalization group improved gauge action and clover improved wilson quark actions"Physical Review. D63(3). 034502-1-034502-11 (2001)
[Publications] CP-PACS collaboration (M,Fukugita et al.): "Sea quark effects on quarkonia"Physical Review. D62(11). 114508-1-114508-13 (2000)
[Publications] CP-PACS collaboration(M,Fukugita et al.): "Dynamical quark effects on light quark masses"Physical Review Letters. 85(22). 4674-4677 (2000)
[Publications] JLQCD collaboration(M,Fukugita et al.): "Pion decay constant for the Kogut-Susskind quark action in quenched lattice QCD"Physical Review. D62(9). 094501-1-094501-15 (2000)
[Publications] JLQCD collaboration(M,Fukugita et al.): "Nucleon decay matrix elements from lattice QCD"Physical Review. D62(1). 014506-014506-19 (2000)
[Publications] M.Fukugita,G-C.Liu,N.Sugiyama: "Limits on neutrino mass from cosmic structure formation"Physical Review Letters. 84(6). 1082-1085 (2000)
[Publications] JLQCD collaboration(M,Fukugita et al.): "B meson leptonic decay constant with quenched lattice NRQCD"Physical Review. D61(7). 074501-1-074501-14 (2000)
[Publications] CP-PACS collaboration(M,Fukugita et al.): "Quenched light hadron spectrum"Physical Review Letters. 84(2). 238-241 (2000)
[Publications] T.Watari,T.Yanagida: "N=2 supersymmetry in a hybrid inflation model"Physics Letters. B499(3-4). 297-304 (2001)
[Publications] F.Borzunati,K.Hamaguchi,T.Yanagida: "Supersymmetric seesaw model for the (H3)-scheme of neutrino masses"Physics Letters. B497(3-4). 259-264 (2001)
[Publications] J.Sato,K.Tobe,T.Yanagida: "A constraint on Yukawa coupling unification from lepton flavor violating processes"Physics Letters. B498(3-4). 189-194 (2001)
[Publications] J.Sato,T.Yanagida: "Low-energy predictions of lopsided family charges"Physics Letters. B493(3-4). 356-365 (2000)
[Publications] K.S.Babu,T.Yanagida: "Natural mass generation for the sterile neutrino"Physics Letters. B491(1-2). 148-150 (2000)
[Publications] T.Asaka,M.Fujii,K.Hamaguchi,T.Yanagida: "Affleck-Dine leptogenesis with an ultralight neutrino"Physical Review. D62(12). 123514-1-123514-10 (2000)
[Publications] T.Asaka,T.Yanagida: "Solving the gravitino problem by axino"Physics Letters. B494(3-4). 297-301 (2000)
[Publications] Y,Nomura,T.Yanagida: "Bulk UID messenger"Physics Letters. B487(1-2). 140-144 (2000)
[Publications] M.Kawasaki,N.Sakai,M,yamaguchi,T.Yanagida: "Topological inflation in supergravity"Physical Review. D62(12). 123507-1-123507-7 (2000)
[Publications] M.Kawasaki,M.Yamaguchi T.Yanagida: "Natural chaotic inflation in supergravity"Physical Review Letters. 85(17). 3572-3575 (2000)
[Publications] Y.Nomura,T.Watari,T.Yanagida: "Quintessence axion potential induced by electroweak instonton effects"Physics Letters. B484(1-2). 103-111 (2000)
[Publications] T.Kanazawa,M.Kawasaki,T.Yanagida: "Double inflation in supergravity and the primordial black hole formation"Physics Letters. B482(1-3). 174-182 (2000)
[Publications] Y,Nomura,T.watari,T.Yanagida: "Mass generation for an ultralight axion"Physical Review. D61(10). 105007-1-105007-5 (2000)
[Publications] Kanazawa,M.Kawasaki,S.Sugiyama,T.Yanagida: "Double inflation in supergravity and the large scale structure"Physical Review. D61(2). 023517-1-023517-9 (2000)
[Publications] T.Asaka,K.Hamaguchi,M.Kawasaki,T.Yanagida: "Leptogenesis in an inflationary universe"Physical Review. D61(8). 083512-1-083512-15 (2000)
[Publications] K.I.Izawa,T.Yanagida: "Dynamical inflation and vacuum selection"Progress of Theoretical Physics. 103(5). 1077-1079 (2000)
[Publications] A.Chodos,N.Kitazawa,H.Minakata and C.M.Sommerfield(ed.): "Dynamics of Gauge Fields : TMU-Yale Symposium"Universal Academy Press. 407 (2000)

2000 Fiscal Year Annual Research Report

ニュートリノ振動現象の研究

Principal Investigator

南方 久和 東京都立大学, 理学研究科, 教授 (00112475)

Research Products

[Publications] H.Minakata and H.Nunokawa: "Inverted Hierarchy of Neutrino Masses Disfavored by Supernova 1987A"Physics Letters B.. 504. 301-308 (2001)

[Publications] H.Hiro-Oka and H.Minakata: "Dynamical Pion Production via Parametric Resonance from Disoriented Chiral Condensate"Physical Review C. 61. 044903 (2000)

[Publications] H.Minakata and H.Nunokawa: "Measuring Leptonic CP Violation by Low Energy Neutrino Oscillation Experiments"Physics Letters B. 495. 369-377 (2000)

[Publications] A.Chodos,F.Cooper,W.Mao,H.Minakata,and A.Singh: "Two-Dimensional Model with Chiral Condensate and Cooper Pairs having QCD-like Phase Structure"Physical Review D. 61. 045011 (2000)

[Publications] 浅川正之,南方久和: "カイラル対称性の破れによるドメイン構造(解説)"日本物理学会誌. 55. 263-272 (2000)

[Publications] H.Athar,M.Jezabek and O.Yasuda: "Effects of Neutrino Mixing on High-energy Cosmic Neutrino Flux"Physical Review D. 62. 103007 (2000)

[Publications] N.Kitazawa,N.Maru and N.Okada: "R Mediation of Dynamical Supersymmetry Breaking"Physical Review D. 63. 015005 (2001)

[Publications] N.Kitazawa,N.Maru and N.Okada: "Models of Supersymmetry Breaking with Gauged U(1)(R)Symmetry"Nuclear Physics B. 586. 261-274 (2000)

[Publications] N.Kitazawa,N.Maru and N.Okada: "Dynamical Supersymmetry Breaking with Gauged U(1)(R)Symmetry"Physical Review D. 62. 077701 (2000)

[Publications] N.Kitazawa: "Determination of the Dynamically Generated Yukawa Coupling in Supersymmetric QCD"Physical Review D. 61. 056008 (2000)

[Publications] J.Arafune,T.Yoshida,S,Nakamura,K.Ogure: "Experimental bounds on masses and fluxes of nontopological solitons"Physical Review. D62(10). 105013-1-105013-11 (2000)

[Publications] CP-PACS collaboration (M,Fukugita et al.): "Phase structure and critical temperature of two flavor CD with renormalization group improved gauge action and clover improved wilson quark actions"Physical Review. D63(3). 034502-1-034502-11 (2001)

[Publications] CP-PACS collaboration (M,Fukugita et al.): "Sea quark effects on quarkonia"Physical Review. D62(11). 114508-1-114508-13 (2000)

[Publications] CP-PACS collaboration(M,Fukugita et al.): "Dynamical quark effects on light quark masses"Physical Review Letters. 85(22). 4674-4677 (2000)

[Publications] JLQCD collaboration(M,Fukugita et al.): "Pion decay constant for the Kogut-Susskind quark action in quenched lattice QCD"Physical Review. D62(9). 094501-1-094501-15 (2000)

[Publications] JLQCD collaboration(M,Fukugita et al.): "Nucleon decay matrix elements from lattice QCD"Physical Review. D62(1). 014506-014506-19 (2000)

[Publications] M.Fukugita,G-C.Liu,N.Sugiyama: "Limits on neutrino mass from cosmic structure formation"Physical Review Letters. 84(6). 1082-1085 (2000)

[Publications] JLQCD collaboration(M,Fukugita et al.): "B meson leptonic decay constant with quenched lattice NRQCD"Physical Review. D61(7). 074501-1-074501-14 (2000)

[Publications] CP-PACS collaboration(M,Fukugita et al.): "Quenched light hadron spectrum"Physical Review Letters. 84(2). 238-241 (2000)

[Publications] T.Watari,T.Yanagida: "N=2 supersymmetry in a hybrid inflation model"Physics Letters. B499(3-4). 297-304 (2001)

[Publications] F.Borzunati,K.Hamaguchi,T.Yanagida: "Supersymmetric seesaw model for the (H3)-scheme of neutrino masses"Physics Letters. B497(3-4). 259-264 (2001)

[Publications] J.Sato,K.Tobe,T.Yanagida: "A constraint on Yukawa coupling unification from lepton flavor violating processes"Physics Letters. B498(3-4). 189-194 (2001)

[Publications] J.Sato,T.Yanagida: "Low-energy predictions of lopsided family charges"Physics Letters. B493(3-4). 356-365 (2000)

[Publications] K.S.Babu,T.Yanagida: "Natural mass generation for the sterile neutrino"Physics Letters. B491(1-2). 148-150 (2000)

[Publications] T.Asaka,M.Fujii,K.Hamaguchi,T.Yanagida: "Affleck-Dine leptogenesis with an ultralight neutrino"Physical Review. D62(12). 123514-1-123514-10 (2000)

[Publications] T.Asaka,T.Yanagida: "Solving the gravitino problem by axino"Physics Letters. B494(3-4). 297-301 (2000)

[Publications] Y,Nomura,T.Yanagida: "Bulk UID messenger"Physics Letters. B487(1-2). 140-144 (2000)

[Publications] M.Kawasaki,N.Sakai,M,yamaguchi,T.Yanagida: "Topological inflation in supergravity"Physical Review. D62(12). 123507-1-123507-7 (2000)

[Publications] M.Kawasaki,M.Yamaguchi T.Yanagida: "Natural chaotic inflation in supergravity"Physical Review Letters. 85(17). 3572-3575 (2000)

[Publications] Y.Nomura,T.Watari,T.Yanagida: "Quintessence axion potential induced by electroweak instonton effects"Physics Letters. B484(1-2). 103-111 (2000)

[Publications] T.Kanazawa,M.Kawasaki,T.Yanagida: "Double inflation in supergravity and the primordial black hole formation"Physics Letters. B482(1-3). 174-182 (2000)

[Publications] Y,Nomura,T.watari,T.Yanagida: "Mass generation for an ultralight axion"Physical Review. D61(10). 105007-1-105007-5 (2000)

[Publications] Kanazawa,M.Kawasaki,S.Sugiyama,T.Yanagida: "Double inflation in supergravity and the large scale structure"Physical Review. D61(2). 023517-1-023517-9 (2000)

[Publications] T.Asaka,K.Hamaguchi,M.Kawasaki,T.Yanagida: "Leptogenesis in an inflationary universe"Physical Review. D61(8). 083512-1-083512-15 (2000)

[Publications] K.I.Izawa,T.Yanagida: "Dynamical inflation and vacuum selection"Progress of Theoretical Physics. 103(5). 1077-1079 (2000)

[Publications] A.Chodos,N.Kitazawa,H.Minakata and C.M.Sommerfield(ed.): "Dynamics of Gauge Fields : TMU-Yale Symposium"Universal Academy Press. 407 (2000)

南方久和東京都立大学, 理学研究科, 教授 (00112475)