Physics of Lepton Flavor Mixing

轻子风味混合的物理原理

基本信息

批准号：
09640370
负责人：
MINAKATA Hisakazu
金额：
$ 0.7万
依托单位：
TOKYO METROPOLITAN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
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-09640370/
关键词：
Neutrino mass Flavor mixing 3 generation leptons CP violation Dark matter long-baseline neutrino experiment Majorana neutrino Double beta decay 三世代ニュートリノシーソー機構シ-ソ-機構バリオン数非対称性

项目摘要

During the research term 1997-98 I concentrated on two topics, (1) CP Violation in the Lepton Sector, and (2) Dark Matter Neutrino Hypothesis ; experimental constraints and how to test it.(1) I, in collaboration with Hiroshi Nunokawa (Univ.de Campinas, Brazil), studied the problem of how to measure leptonic CP violation in long-baseline neutrino oscillation experiments. There exists a notorious problem in such measurement ; it is the problem of the matter effect pollusion. That is, the genuine CP violation effect due to the leptonic Kobayashi-Maskawa phase could be masked by that due to matter effect in the IEarth. We have presented a formalism based on matter effect peturbation theory by which one can obtain bird-eye view of the interplay between these two effects. It will enable us to select out the most feasible channel of the experiment searching for the genuine phase CP violation. Moreover, we have proposed a new strategy for sensitive detection of CP violation by setting up an intermediate detector in a dedicated long-baseline experimennt.(2) The neutrino dark matter hypothesis has been topics of interests as an interesting possibility of explaining structure formation in a consistent way with COBE data. I, in collaboration with Osamu Yasuda (TMU), demonstrated that there exist severe constraints on that hypothesis in the standard three-flavor mixing scheme due to the solar and the atmospheric neutrino observation as well as the reactor and accelerator data. We have shown with constraints imposed by CHOOZ reactor experiment that the dark matter neutrinos must have an almost degenerate mass spectrum. Furthermore, we have shown that if neutrinos are Majorana particles this possibility will be severely tested within 5 years by the coming new double beta decay experiment.

在1997 - 98年的研究期间，我集中在两个主题上，（1）Lepton部门的CP违规，以及（2）暗物质中微子假设；（1）I，与尼古川（Univ.de Campinas，巴西）合作研究了如何在长基碱基中性振荡实验中测量缓慢的CP违规的问题。在这种测量中存在一个臭名昭著的问题；这是物质影响污染的问题。也就是说，由于IEARTH的物质效应，可以掩盖了由于麻血性的Kobayashi-Maskawa阶段而引起的真正的CP违规效应。我们提出了一种基于物质效应糊状理论的形式主义，通过该形式可以通过该理论获得这两种效果之间相互作用的鸟眼观点。这将使我们能够选择实验中最可行的渠道，以寻找真正的CP违规阶段。此外，我们通过在专用的长基线实验中设置中间检测器来提出了一种对CP违规敏感检测的新策略。（2）中微子暗物质假设是利益的主题，是解释在解释结构形成的有趣可能性。 COBE数据的一致方法。 I，与Osamu Yasuda（TMU）合作，证明，由于太阳能和大气中微子观测以及反应堆和加速器数据，标准三味混合方案中的该假设存在严重限制。我们已经通过Chooz反应器实验施加的约束表明，暗物质中微子必须具有几乎变质的质谱。此外，我们已经表明，如果中微子是主要粒子，则将通过即将到来的新的双重β衰变实验在5年内严格测试这种可能性。