Study of T-invariance in K^+ Decay at KEK Proton Synchrotron

KEK 质子同步加速器 K^ 衰变中 T 不变性的研究

基本信息

批准号：
06044216
负责人：
IMAZATO Jun
金额：
$ 3.65万
依托单位：
National Laboratory for High Energy Physics (KEK)
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06044216/
关键词：
Time Reversal Invariance K-meson Decay Muou Polarization Proton Synchrotron Superconducting Spectrometer Stopped Muou CsI(Tl)sciutillata Fiber Target K^+崩壊 Tの破れ CsI(Tl)ポラリメータ

项目摘要

The purpose of this project is to study the problem of time reversal invariance (TRI) and to search for its violation in a kaon decay process K^+ *pi^0mu^+nu.We looked for transverse muon polarization which indicates violation of TRI by using the Superconducting Toroidal Spectrometer at the KEK proton synchrotron. This study can shed light to the origin of CP-violation which is one of the important issues of the present particle physics.This project was carried out by an international collaboration of Japan, Russia (Instutute for Nuclear Research, Russian Academy of Sciences) and Canada (TRIUMF and others).Although the experiment itself is one of the KEK-PS experiments, we spent years to construct and preapre the detector by international cooperative work, because the size of the experiment is large.In 1995 experimental apparatus was completed and measurement was started.The one of the mail elemens of the detector is a photon detector to detect pi^0 from the K^+*pi^0mu^+nu decay.This d … More etector is comprise 768 CsI(Tl) crystals and was designed by Japan-Russia collaboration.The crystals were produced at Kharikov in Ukraina under the conduct of INR,and brought to KEK where further preparation has been done. A barrel of CsI(Tl) was completed in 1995 and was installed at the Toroidal Spectrometer in last September after a careful test, tuning and a calibration measurement.An active target and one of the tracking chambers, C1, have been made by the Japan-Canada collaboration.They were assembled at the TRIUNF shop and brought to KEK last summer.They were also installed in the setup and tuned.The whole experimental apparatus became ready in last fall and the test and tuning of the system was started using K^+ beam from K5 at KEK-PS.The gain adjustment of CsI(Tl) crystals was performed by the measurement of K^+*pi^0pi^+ and K^+*mu^+nu decays.The measurement was also done for the design of the muon polarimeter, such as the degrader thickness.The positron counters were carefully aligned and their threshold was tuned.After these preparation measurements, a real measurement of the muon polarization started in January 1996.The measurement will continue further in next fiscal year to get enough statistical accurscy in the result.But we started the analysis of taken data. Less

该项目的目的是研究时间逆转不变性（TRI）的问题，并在Kaon衰变过程中寻找违规行为K^+ *pi^0mu^0mu^+ nu。我们寻求横向muon极化，这表明通过使用Kek Proton Synchrotron的超导式子弹光谱仪使用超导式子弹仪，这表明TRI违反了TRI。 This study can shed light to the origin of CP-violation which is one of the important issues of the present particle physics.This project was carried out by an international collaboration of Japan, Russia (Instutute for Nuclear Research, Russian Academy of Sciences) and Canada (TRIUMF and others).Although the experiment itself is one of the KEK-PS experiments, we spent years to construct and preapre the detector by international cooperation work, because the size of the experiment很大。 INR，并带到Kek进行了进一步的准备。 1995年完成了CSI（TL）的桶（TL），并在经过仔细的测试，调查和校准测量之后于去年9月安装在环形光谱仪上。主动目标和一个跟踪室C1，由日本 - 加拿大的合作进行。在去年秋天准备就绪以及系统的测试和调整是使用K5的K5开始的测试和调整。通过测量k^+*pi^0pi^0pi^+和k^+*mu^+nu衰变的k^+*pi^0pi^0pi^0pi^0pi^0pi^0pi^0pi^0pi^0pi^+nu的衰减的增益。调整了阈值。这些准备测量值是对MUON极化开始的实际测量，该量从1996年1月开始。测量将在下一个会计年度继续进行，以在结果中获得足够的统计准确性。但是我们开始对数据进行分析。较少的