Experimental Study on Quark-Gluon-Plasma at BNL
Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants|
|Research Institution||Institute for Nuclear Study, University of Tokyo|
HOMMA Saburo Professor Institute for Nuclear Study, University of Tokyo, 原子核研究所, 教授 (10004326)
O. HANSEN 米国ブルックヘブン国立研究所, 主任研究員
KIMURA Kikuo Research Associate Department of Physics, Kyushu University, 理学部, 助手 (60108636)
SUGITATE Tohru Research Associate Department of Physics, Hiroshima University, 理学部, 助手 (80144806)
AKIBA Yasuyuki Research Associate Institute for Nuclear Study, University of Tokyo, 原子核研究所, 助手 (80192459)
NAGAE Tomofumi Research Associate Institute for Nuclear Study, University of Tokyo, 原子核研究所, 助手 (50198298)
HAMAGAKI Hideki Research Associate Institute for Nuclear Study, University of Tokyo, 原子核研究所, 助手 (90114610)
NISHIKAWA Koichiro Associate Professor Institute for Nuclear Study, University of Tokyo, 原子核研究所, 助教授 (60198439)
HASHIMOTO Osamu Associate Professor Institute for Nuclear Study, University of Tokyo, 原子核研究所, 助教授 (50092292)
HANSEN Ole Chief Scientist Brookhaven National Laboratory
|Project Period (FY)
1991 – 1992
Completed(Fiscal Year 1992)
|Budget Amount *help
¥9,000,000 (Direct Cost : ¥9,000,000)
Fiscal Year 1992 : ¥4,500,000 (Direct Cost : ¥4,500,000)
Fiscal Year 1991 : ¥4,500,000 (Direct Cost : ¥4,500,000)
|Keywords||High Energy and High Density Nuclear Matter / High Energy Heavy-Ion Collision / Two-Particle Correlation / Quark-Gluon-Plasma / QGP / 高エネルギ-重イオン反応 / クォ-ク・グル-オン・プラズマ / 相変化 / 高密度原子核物質 / 高エネルギ-原子核反応|
The experiment with high-intensity 14.5 AGeV Si-beams and the first-round experiment with 11 AGeV Au-beams have been carried out by the Japan-US international collaboration in high energy heavy ion collisions at the AGS, Brookhaven National Laboratory, USA.
Primary goals of the experiment are (1) to study the two-particle correlations for pions and Kaons, and (2) to measure the rarely-produced hadrons (i.e. K-and anti-proton) with good statistics using the experimental system with a magnetic spectrometer as a central device.
Space-time evolution of nucleus-nucleus collisions could be investigated through two-particle correlation measurement. Trial of measuring K-and anti-proton were made before, but low statistics prevented us to deduce any conclusions for their productions.
In order to achieve the goals, we built a special trigger system by which particle identification in the trigger-level was made possible. Stringent event selection capability made it possible to run with high-intensity beams.
Data analyses of two particle correlations are in progress, and preliminary result shows that source size measuremed by pions is significantly smaller than that measured by Kaons.
Anti-proton yield was consisten with the model calculation with no anti-protons absorption in nuclear matter, which strongly contradicts to the naive expectation.
With the completion of AGS-Booster, experiments with heavy ions up to Au became possible. We can expect a better condition to study unclear matter at extreme conditions with heavy ions. The first Au beam was available in May, 1992, and we had a prelminary short run. Purity of Au beam was better than 99%. Measurements of transverse and forward energy flow were made. Measurement of particle spectra at backward angle with spectrometer were also tried.
Data analysis going on, and the construction of a new spectrometer which covers the forward angular region is in progress.
Research Output (11results)