Research for neutrino oscillation by direct detection of tau-lepton

直接检测τ轻子研究中微子振荡

• 批准号: 09304031
• 负责人: NIWA Kimio
• 金额: $ 22.72万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09304031/
• 关键词: Tau-neutrino; Neutorino oscillation; Emulsion; Dark matter; Elementary particle; ニュートリノ; クォークレプトン; ダークマター; ダ-クマタ-; エマルション

Ultra Track selector (UTS) will make big change of the usage of the emulsion.The CHORUS experiment is organized to study the mass of tau-neutrino using mu-neutrmno to tau-neutrino oscillation . The emulsion target was used to detect neutrino interactions and to recognize the tau-neutrmno from other neutrinos.The first automatic emulsion scanning system (New Track Selector) was developed. Up to now, lOOK neutrino interactions were located in the emulsion and were analyzed short fight decays in emulsion targets. The tau decay search was at first focused on the decay channel of nu_<mu>*nu_<tau>, this channel has almost no background. We found zero tau-neutrino interaction and obtained the mixing limit of mu to tau sin^2 (2theta@mutau@E2) >O.OO1, (for DELTAm^2 > 10eV^2) . This result is not contradict to Super-K result which was recently presented in conference of Neutrino physics and Astrophysics (NEUTRINO'98) at Takayama city. Our result is 5 times better than the past world record E531 in FNAL 1978.Recently we finished the development of "Ultra fast Track Selector" which has 10 times faster than "New Track Selector".

超径迹选择器(UTS)将使乳剂的使用发生很大的变化，为了研究超中微子的质量，我们组织了一个合唱实验来研究超中微子的质量。利用乳胶靶探测中微子相互作用，并将tau中微子与其他中微子区分开来。研制了第一套乳胶自动扫描系统(新径迹选择器)。到目前为止，Look中微子相互作用位于乳化液中，并在乳胶靶中进行了短时间的战斗衰变分析。Tau衰变的搜索最初集中在Nu_&lt；Mu&gt；*nu_&lt；tau&gt；的衰变通道上，该通道几乎没有背景。我们发现了零的tau-中微子相互作用，并得到了u与tau sin^2(2theta@mutau@E_2)和gt；0.0001的混合极限(对于DELTAm^2和gt；10eV^2)。这一结果与最近在高山市举行的中微子物理和天体物理会议(中微子‘98)上发表的Super-K结果并不矛盾。我们的成绩是1978年4月打破的世界纪录E531的5倍。最近，我们完成了“超快轨道选择器”的研制，其速度比“新轨道选择器”快了10倍。

项目成果

S.Aoki: "Quaifree p(K・,K^+)Ξ^+ reaction in nuclear emulsion" Nuclear Physics. A644. 365-385 (1998)

S.Aoki：“核乳液中的 Quaifree p(K·,K^+)Ξ^+ 反应”核物理 365-385。

E.Eskut: "Search for Search for ν_μ→ν_τ using the τ decay modes into a single charged particle." Phys.Lett.B434. 205-213 (1998)

E.Eskut：“使用 τ 衰变模式搜索 ν_μ→ν_τ 到单个带电粒子。”Phys.Lett.B434 (1998)。

E.Eskut, et al.: "A search for nu_<mu>*nu_<tau> oscillation" Phys.Lett.B424. 202-212 (1998)

E.Eskut 等人：“寻找 nu_<mu>*nu_<tau> 振荡”Phys.Lett.B424。

E.Arik: "The CHORUS experiment to search for ν_μ→ν_τ oscillation" Nucl.Inst.Meth.A401. 7-44 (1997)

E.Arik：“寻找 ν_μ→ν_τ 振荡的 CHORUS 实验”Nucl.Inst.Meth.A401 (1997)。

E.Eskut et al.: "Search for νμ→ντ oscillation by the CHORUS experiment." Phys.Lett.(in press).

E.Eskut 等人：“通过 CHORUS 实验搜索 νμ→ντ 振荡。”（正在出版）。