Double Beta decays and Related Subjexts by Ultra Rare-process Nuclear Spectroscopy

双贝塔衰变和超稀有过程核光谱的相关主题

• 批准号: 03402005
• 负责人: EJIRI Hiroyasu
• 金额: $ 22.02万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03402005/
• 关键词: Nuclear rare decay; Double beta decays; Neutrino; Dark matter; Charge non-conservation; Pauli Principles; Nucleon decay; 右巻き弱相互作用; 暗黒物質探索; ニュートリノ質量; 右巻弱相互作用; 二重ベ-タ崩壊; 電荷非保存; パウリ原理の破れ; 電子の構造

1. Double beta decays and neutrino(1) Neutrinoless Double beta decays of ^<100>Mo have been measured for studying fundamental properties of neutrino and the validity of electro-weak standard model means of ELEGANT V detector. (2) Double beta decays with two neutrino of ^<100>Mo and ^<116>Cd were studied and the finite half lives for both nuclei were observed. (3) New type drift chambers, which are very sensitive to alpha particles emitted from residual radioactivities, have been installed in the ELEGANTS V detector.2. Search for dark matterNew particles of dark matter candidates have been searched by means of large NaI with the total mass of 0.76ton in ELEGANTS V detector. NaI detector was found to be very sensitive to spin-coupled dark matter candidates.3. Test of Conservation Laws of Particle and Nuclear PhysicsElectron stability and nucleon stability have been checked by using the electron and nucleon in NaI detector itself in ELEGANTS V detector. These stabilities give one of the highest upperlimits of charge nonconserving decay of electron, breakings of Pauli principle, and mode independent nucleon decays.4. Ultra-rare Nuclear reactionsELEGANTS IIIs detector with neutron scatterer was shown to be very sensitive in the search for rare neutron events such as d-d fusion at room temperature. The observed fusion rate was obtained as <1.6・10^<-24> (ddn) fusions/(dd)pair/sec.5. Radioactivity in MeteoritesGamma rays from radioactivities in meteorites were measured by means of ELEGANTS IIIs detector. Concentration of ^<26>Al in large meteorites with total mass of several hundred gram can be measured nondestructively in an order of dpm/kg.

1. (1)为了研究中微子的基本性质和ELEGANT V探测器电弱标准模型手段的有效性，测量了^<100>Mo的双β衰变。(2)研究了Mo ^<100>和Cd ^<116>两个中微子的双β衰变，并观察了两个原子核的有限半衰期。(3)在ELEGANTS V探测器上安装了新型漂移室，该漂移室对残留放射性释放的α粒子非常敏感。寻找暗物质用总质量为0.76吨的大型NaI在ELEGANTS V探测器上搜索到了新的暗物质候选粒子。发现NaI探测器对自旋耦合的候选暗物质非常敏感。粒子与核物理守恒定律的检验在ELEGANTS V探测器中，利用NaI探测器本身的电子和核子来检验电子稳定性和核子稳定性。这些稳定性给出了电子的电荷非守恒衰变、泡利原理的破断和模式无关的核子衰变的最高上限之一。采用中子散射体的egants iii型探测器在室温下对稀有中子事件（如d-d聚变）的探测非常敏感。观察到的融合速率为<1.6·10^<-24> (ddn)个融合/(dd)对/秒5。陨石中的放射性用ELEGANTS iii型探测器测量了陨石中放射性物质的伽马射线。总质量为几百克的大陨石中^<26>的铝浓度可以无损地以dpm/kg数量级测量。

项目成果

E.Choi: "Application of Ge Detector to Search for Fast Neutrons from DD Fusion in Deuterized Pd" Jpn.J.Appl.Phys.32. 3964-3967 (1993)

E.Choi：“应用 Ge 探测器搜索氘化 Pd 中 DD 聚变的快中子”Jpn.J.Appl.Phys.32。

H.Ejiri: "Nuclear deexcitation of nucleon holes associated with nucleon decays in nuclei" Physical Review C. 48. 1442-1444 (1993)

H.Ejiri：“与原子核中的核子衰变相关的核子空穴的核去激发”物理评论 C. 48. 1442-1444 (1993)

H.Ejiri: "Double beta decays studied by ELEGANTS V" Nuclear Physics B. (出版予定). (1994)

H.Ejiri：“ELEGANTS V 研究的双β衰变”核物理学 B.（即将出版）。

T.Watanabe, H.Ejiri, K.Okada, N.Kamikubota, H.Sano, T.Shima, J.Tanaka, K.Fushimi, H.Kinoshita, Y.Nagai, and T.Shibata: "Two Neutrino Double Beta Decay of ^<100>Mo with ELEGANTS-IV" Proc. 14th Europhysics Conf. on "Rare Nuclear Decays and Fundamental Proce

T.Watanabe、H.Ejiri、K.Okada、N.Kamikubota、H.Sano、T.Shima、J.Tanaka、K.Fushimi、H.Kinoshita、Y.Nagai 和 T.Shibata：“两个中微子双贝塔

N.Kudomi, T.Shima, H.Ejiri, J.Tanaka and T.Watanabe: "Preparation of large and thin source films for studying nuclear rare decays" Nuclear Instrument and Methods in Physical Research A. 322. 53-56 (1992)

N.Kudomi、T.Shima、H.Ejiri、J.Tanaka 和 T.Watanabe：“用于研究核稀有衰变的大而薄源膜的制备”核物理研究仪器和方法 A. 322. 53-56 (1992)