Neutrino research by OPERA detector

2015 Fiscal Year Final Research Report

• Project/Area Number: 24244027
• 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): NAKANO Toshiyuki 名古屋大学, 大学院・理学研究科, 講師 (50345849) ; SATO Osamu 名古屋大学, エコトピア科学研究所, 助教 (20377964) ; KOMATSU Masahiro 名古屋大学, 教養教育院, 准教授 (80345842) ; 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): 2012-04-01 – 2016-03-31
• Keywords: ニュートリノ / タウニュートリノ / 出現法 / 原子核乾板

Outline of Final Research Achievements

Until today, four clear tau neutrino events have been detected. The existence of the neutrino oscillation, i.e. muon-neutrino to tau-neutrino, has been confirmed with the statistical significance of 4.2sigma. In one of the detected event, the decay daughter was identified as muon with minus charge. This means that the event is tau-neutrino event not the anti-tau-neutrino event. By this fact, it is confirmed with 98% probability that muon-neutrino oscillate to tau-neutrino (not anti-tau neutrino). The search of electron- neutrino has been tried and 19 events was identified with 21.3 expectation. This result gave an upper limit on the osicllation parameter theta13 and gave limitation on the oscillation parameter region of LNSD claimed oscillation.

Free Research Field

素粒子物理学実験