Study of CP Violation in Weak Interaction

我们分析了Fermilab E731实验的数据，并公布了CP破坏参数Re（ε ′/ε）的最终结果。我们还分析了Fermilab E799-I实验的数据，该实验的目的是寻找许多罕见的K_L衰变。我们已经发表了关于K_L*pi^0ee，K_L*pi^0mumu，K_L *pi^0nunu，K_L*eeee，K_L*eegammagamma，K_L*pi^0pi^0gamma，pi^0*ee和pi^0*mue的新结果。9.2.费米实验室KTeV实验的准备费米实验室KTeV实验将于1996年7月开始，运行时间为2年。该实验将测量CP破坏参数Re（ε ′/ε ′），其精度提高6倍，达到1 × 10 - 4<-4>。它也将搜索许多稀有的K_L衰变，灵敏度提高了两个数量级。我们对实验作出了以下贡献。我们与UCLA和滨松光子学公司合作，为新的CsI量热计开发一种新型光电管。该管被设计成具有极好的线性。我们建立了一个新的光电管测试系统，并测量了2400管的线性度和速率依赖性，精度&lt;0.2%。我们与费米实验室合作开发了一种新的数据采集系统。该系统由一个大型存储矩阵和高性能计算机组成。该系统可以读入并全面分析以20 kHz频率传入的8 kbyte事件，并将选定的事件写入磁带。*我们设计、测试并制造了一个专门的光子否决计数器，放置在CsI量热计的束孔周围。本文用蒙特卡罗模拟方法估计了各种稀有K_L衰变的灵敏度和本底能级。我们还开发了衰变的分析代码。

We have analyzed the data from Fermilab E731 experiment, and published the final result on the CP violation parameter, Re (epsilon'/epsilon). We have also analyzed the data from Fermilab E799-I experiment, whose purpose was to search for many rare K_L decays. We have published new results on K_L*pi^0ee, K_L*pi^0mumu, K_L*pi^0nunu, K_L*eeee, K_L*eegammagamma, K_L*pi^0pi^0gamma, pi^0*ee, and pi^0*mue. The first three decays are expeted to have a large direct CP violation amplitude.9.2.Preparation of Fermilab KTeV experimentFermilab KTeV experiment will begin in July of 1996, and will run for 2 years. The experiment will measure the CP violation parameter Re (epsilon'/epsilon) with 6 times better accuracy, to 1x10^<-4>. It will also search for many rare K_L decays with a sensitively improved by two orders of magnitudes. We have made the following contributions to the experiment.*We have worked UCLA and Hamamatsu Photonics to develop a new type of phototubes for the new CsI calorimeter. The tube was designed to have an excellent linearity. We built a new phototube testing system, and measured the linearity and rate dependence of the 2400 tubes with <0.2% accuracy.*We have collaborated with Fermilab to develop a new data acquisition system. The system consists of a large memory matrix and high performance computers. This system can read in and fully analyze 8kbyte events coming at 20kHz, and write out selected events to tape.*We have designed, tested, and produced a specialized photon veto counter to be placed around the beam holes in the CsI calorimeter.*We have estimated the sensitivity and background levels for various rare K_L decays by using Monte Carlo simulation. We have also developped analysis codes for the decays.