| Project/Area Number |
04402006
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
核・宇宙線・素粒子
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
NAGASHIMA Yorikiyo Osaka Univ., Physics Dept.Professor, 理学部, 教授 (90044768)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HAZUMI Masashi Osaka Univ., Physics Dept.Research Associate, 理学部, 助手 (20263197)
TAKITA Masato Osaka Univ., Physics Dept.Research Associate, 理学部, 助手 (20202161)
HABA Junji KEK,Physics Dept.Associate Professor, 物理部, 助教授 (60180923)
YAMANAKA Taku Osaka Univ., Physics Dept.Associate Professor, 理学部, 助教授 (20243157)
|
|---|
| Project Period (FY) |
1992 – 1995
|
| Project Status |
Completed (Fiscal Year 1995)
|
| Budget Amount *help |
¥33,000,000 (Direct Cost: ¥33,000,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1994: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1993: ¥8,600,000 (Direct Cost: ¥8,600,000)
Fiscal Year 1992: ¥20,600,000 (Direct Cost: ¥20,600,000)
|
|---|
| Keywords | Weak interaction / CP violation / Neutral kaon / CsI,photomultiplier / Data acquisition system / Photon veto counter / ガンマ線検出器 / 光電子増倍管 / 稀崩壊 / CsIカロリメータ |
|---|
| Research Abstract |
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 experiment
Fermilab 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.
|
