Discovery of the Higgs Particle and Studies toward the Understanding of the Mass-Acquiring-Mechanism of Elementary Particles

2015 Fiscal Year Final Research Report

• Project Area: Particles Physics opening up the Tera-scale horizon using LHC
• Project/Area Number: 23104002
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: TOKUSHUKU Katsuo 大学共同利用機関法人高エネルギー加速器研究機構, 素粒子原子核研究所, 所長 (80207547)
• Co-Investigator(Kenkyū-buntansha): UNNO Yoshinobu 高エネルギー加速器研究機構, その他部局等, 名誉教授 (40151956) ; UKEGAWA Fumihiko 筑波大学, 数理物質科学研究科, 教授 (10312795)
• Co-Investigator(Renkei-kenkyūsha): TSUNO Soshi 高エネルギー加速器研究機構, 素粒子原子核研究所, 研究機関講師 (30451834) ; MASUBUCHI Tatsuya 東京大学, 素粒子物理国際研究センター, 特任助教 (20512148) ; NAKAMURA Koji 高エネルギー加速器研究機構, 素粒子原子核研究所, 助教 (00554479) ; HARA Kazuhiko 筑波大学, 数理物質科学研究科, 講師 (20218613) ; IWASAKI Hiroyuki 高エネルギー加速器研究機構, その他部局等, 名誉教授 (40151724) ; TAKASHIMA Ryuichi 京都教育大学, 教育学部, 准教授 (60163200) ; SATO Koji 筑波大学, 数理物質科学研究科, 講師 (30422190) ; OKAWA Hideki 筑波大学, 数理物質科学研究科, 助教 (10746960)
• Project Period (FY): 2011-04-01 – 2016-03-31
• Keywords: 素粒子実験 / ヒッグス粒子 / 標準理論 / ビクセル検出器 / 耐放射線検出器 / 国際研究者交流スイス

Outline of Final Research Achievements

We have performed high-energy proton-proton collision experiment at the Large Hadron Collider(LHC) at CERN and discovered a new particle with the mass around 125 GeV. With careful measurements for its mass, production cross section and branching ratios, we have found that the particle is consistent with the long-sought Higgs particle which the Standard Model(SM) of the particle physics has been predicted. Given its measured mass value and the fact that no other new particles emerged, our results give a significant constraint on building a theory beyond the SM.
In parallel to the Higgs analysis, we have developed radiation-hard pixel detector at the future experiment for the further precision measurements. The basic R&D for the pixel detector has been completed. We have identified radiation-weak location in the device and improved the layout.

Free Research Field

素粒子物理学実験