KOTO Group@Osaka
Yamanaka-Taku Laboratory

[修士論文] [博士論文]

2013高島 悠太TAKASHIMA, Yuta
2013豊田 高士TOYODA, Takashi
KOTO実験に用いるInner Barrel検出器の製作と宇宙線ミューオンを用いた性能評価
2012伴野真太郎BANNO, Shintaro
J-PARC KOTO実験のカロリメータ下流に設置するガンマ線検出器の開発とその性能評価
2011中谷 洋一NAKAYA, Yoichi
2011柳田 陽子YANAGIDA, Yoko
J-PARC KOTO実験CsIカロリメータのための光学接続シリコーンの製作と長期安定性の評価
2010杉山 泰之SUGIYAMA, Yasuyuki
J-PARC E14 KOTO実験のためのデータ収集システムの開発及び構築
2008吉元 寛貴YOSHIMOTO, Hiroki
2008Lee Jong-wonLEE, Jongwon
2007佐藤 和史SATO, Kazufumi
CsI calorimeter 上に作られる cluster shape を用いた background の識別
2006岩井 瑛人IWAI, Eito
KL-> 3γ崩壊の探索
2014李 宗垣Lee, Jong-won
Energy Calibration Method for the KOTO CsI Calorimeter
The KOTO experiment aims to observe the rare decay of long lived neutral kaons,KL- > π 0ν ν, with the sensitivity of the Standard Model prediction. The detectors of the KOTO experiment were constructed at J-PARC. The electromagnetic calorimeter is the only detectorto measure energies and hit positions of gamma which are used for the KL- > π 0ν ν reconstruction. To guarantee the performance of the calorimeter, an accurate output monitoring method and a precise energy calibration method are required. I built an output monitoring system using Laser light source, and determined its performance. For the calibration of the calorimeter, thecalibration sources are limited to the cosmic ray events and KL decay events, because thereare no other detectors which can measure energy or momentum of particles independently. In addition, the KOTO experiment will run for several years, and thus the calibration has to be done simultaneously with the data taking to secure the reliabilities of data. Because of these restrictions, I developed and studied a new calibration method which uses KL- > 3π 0 decay events and occasional absolute energy calibration runs. This method can calibrate the calorimeter with an accuracy less than 1%.
2012岩井 瑛人IWAI, Eito
CsI calorimeter for the J-PARC KOTO experiment
The KOTO experiment was designed and is being prepared at J-PARC (Japan Proton Accelerator Research Complex), to observe the rare decay of long lived neutral kaons, KL- > π 0ν ν with the sensitivity of the Standard Model prediction. An electromagnetic calorimeter for the KOTO experiment was upgraded to have a finer granularity and waveform readout capability.
We measured the performance of the calorimeter, and reproduced the obtained performance based on the first principle. We also developed a new analysis method to discriminate incident angles by using shower shape information obtained with the finer granularity. By applying the new method, one of the backgrounds, the KL-> γ γ decay in the beam halo, was estimated to be suppressed by a factor of 50, and the total number of background events was estimated to be reduced to less than the number of signal events predicted by the Standard Model.

Last updated 2013/03/31 top /goto Takulab top