Background studies in Rare Kaon decay experiment based on measurements of beam properties

2015 Fiscal Year Final Research Report

• Project/Area Number: 25400309
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: NOMURA Tadashi 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, 准教授 (10283582)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: K中間子稀崩壊 / 大強度中性ビーム / J-PARC

Outline of Final Research Achievements

In the rare Kaon decay experiment, which utilizes the J-PARC accelerator, the physics analysis of the data taken in 2013 for 100 hours was performed. The sensitivity equivalent to the current world record was achieved as the result. The analysis also revealed that background rejection is necessary to proceed to further sensitivity, especially for the backgrounds due to neutron interactions. After developing and implementing devices and methods to evaluate the quality of the neutral beam, data taking was resumed in 2015. Data amount taken in 2015 corresponds to improvement of the sensitivity by a factor of 20, compared with current world records. Combined with data for background evaluation, the data analysis is ongoing to extract a new result.

Free Research Field

素粒子物理学実験