The measurement of a tau-neutorino mass

牛中子质量的测量

• 批准号: 05044047
• 负责人: NIWA Kimio
• 金额: $ 6.72万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05044047/
• 关键词: Neutrino oscillation; Neutrino mass; Tau-neutrino; Dark matter; Emulsion; Scintillating fiber

CHORUS is the international project using the neutrino beam from super proton synchrotrn (SPS) of CERN (Center of Europ organization for Research of Nuclus). The object of this project is to observe the mass of tau-neutrino by the method of the oscillation from mu-neutrino to tau-neutrino. The identification of tau-neutrino could be done by detecting the produced tau by observing the trace of tau from produced point to the decay point in the photographic nucler emulsion.The detecter have many parts, target spectrometer calorimeter and muon spectrometer. We are contributing on the target the most important target of this experiment. This target has the sandwich structure of emulsion sheets and fiber trackers.The neutrino exposure has been finished on Novenber in 1995. The emulsion analysis, the most difficult job in this project, has been done by using Automatic emulsion analysis system originally developed by physists of Nagoya university. The number of analyzed neutrino interaction in the emulsion is more than 7700 neutorino interactions by 4 month scanning. This number is about 15% of all CHORUS, but already this number is 2 times higher than the most sensitive similler experiment, named E531 done in 1978. This experiment is sensitive to 1 eV in tauneutrino mass and 1% in mixing tau-neutrino to mu-neutrino.To finish all of the analysis, it take more two years.

合唱是使用CERN的Super Proton Synchrotrn（SP）的中微子束（Nuclus研究中心）的国际项目。该项目的目的是通过从mu-neutrino到tau-neutrino的振荡方法观察tau-neutrino的质量。可以通过观察从产生的点到摄影核乳液中的衰减点的tau的痕迹来检测tau的识别。我们为目标做出贡献是该实验的最重要目标。该目标具有乳液片和纤维跟踪器的三明治结构。中微子暴露于1995年在Novenber上完成。乳液分析是该项目中最困难的工作，是通过使用自动乳液分析系统最初由物理学家开发的。名古屋大学。乳液中分析的中微子相互作用的数量在4个月的扫描中超过7700个NETORINO相互作用。这个数字大约是所有合唱的15％，但是这个数字已经比最敏感的Similler实验高2倍，该实验称为1978年完成的E531。该实验对Tauneutrino质量中的1 eV敏感，将Tau-neutrino与Tau-neutrino混合到1％。 Mu-neutrino。要完成所有分析，需要两年的时间。

项目成果

K.Kodama: "Measurement of the lifetime of charged and neutral beauty hadrons." Prog.Theor.Phys.Vol.89. 679-696 (1993)

K.Kodama：“测量带电和中性美丽强子的寿命。”

K.Niwa: "シンチレーションファイバートラッカーの開発研究" 放射線. 21. 85-119 (1995)

K. Niwa：“闪烁光纤跟踪器的开发研究”《放射学》21. 85-119 (1995)。

K.Kodama: "A study of semileptonic decays of the D_S." Phys.Lett.B309. 483-491 (1993)

K.Kodama：“对 D_S 半轻衰变的研究。”

K.Teraoka: "Radiation damage test of position sensitive scilicon detectors." Nucl.Inst.Meth.A324. 276-283 (1993)

K.Teraoka：“位置敏感硅探测器的辐射损伤测试。”

S.Aoki: "Observation of the muonic decay D_S^+*mu^+upsiron" Prog.Theor.Phys.89. 131-138 (1993)

S.Aoki：“μ 子衰变 D_S^ *mu^ upsiron 的观察”Prog.Theor.Phys.89。