Study of Neutrino by OPERA experiment -Summary and study on cosmic-ray event-

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H02085
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nagoya University
• Principal Investigator: NAKAMURA Mitsuhiro 名古屋大学, 未来材料・システム研究所, 教授 (90183889)
• Co-Investigator(Kenkyū-buntansha): 佐藤 修 名古屋大学, 未来材料・システム研究所, 助教 (20377964) ; 中野 敏行 名古屋大学, 理学研究科, 講師 (50345849) ; 小松 雅宏 名古屋大学, 教養教育院, 准教授 (80345842)
• Co-Investigator(Renkei-kenkyūsha): AOKI Shigeki 神戸大学, 大学院・人間発達環境学研究科, 教授 (80211689) ; SHBUYA Hiroshi 東邦大学, 理学部, 教授 (40170922)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: ニュートリノ / タウニュートリノ / ニュートリノ振動 / 原子核乾板

Outline of Final Research Achievements

OPERA is an experiment to confirm the existence of neutrino oscillation, i.e. existence of neutrino mass, by detecting tau neutrino appearance. From 2000, we started the detector and beam line construction, did beam exposure from 2006 to 2012, have been performing event analysis until today. In 2015, we detected the fifth event and reached to the statistical significance of 5.1σlevel meaning the discovery level. From 2016, by applying looser cut and including the boarder events, the signal number reaches to 10 events with the expected background of 2.0±0.4. The reached significance level is 6.1σ. OPERA has finished the main analysis by this paper although continuing technological R&D using real events for electron neutrino detection and so on for future neutrino experiments.

Free Research Field

素粒子物理学実験