Study of High-Temperature, High-Density Hadronic Matter

1.利用我们在CERN-SPS上建造的动量聚焦谱仪，我们积累了大量的450-GeV质子-核和200-GeV/核子硫-核碰撞的原始数据.我们研制了一种新型的气体切伦科夫探测器作为硫束实验的束流计数器。该计数器工作成功，即使在实际束流强度为2 × 10^6 ions/s时，也能实现36 ps的时间分辨率。包括我们小组在内的NA 44协作以及这些机构获得的结果都经过了仔细的检查。硫铅碰撞中π介子干涉测量的结果将在不久的将来作为一篇论文发表在《核物理》B.5上。我们对K介子干涉测量的初步结果表明，在硫铅碰撞中，K介子的源尺寸比π介子的源尺寸小约1/2. K^+和K^-源的大小没有显著差异。π介子、K介子、质子和反质子的单能谱都可以用强子横质量的单指数函数拟合，并分别导出了这些强子的强子源温度参数.开发了铅-核碰撞的模拟程序。作为未来铅核碰撞的核心探测器之一，我们正在研制一个用于粒子核裂变的气体切伦科夫计数器。

1. Using the momentum focussing spectrometer which we have constructed at the CERN-SPS, we have accumulated a large amount of raw deta on 450-GeV proton-nucleus and 200-GeV/nucleon sulphur-nucleus collisions.2. We have developed a new type of gas Cherenkov detector as a beam counter for the sulphur-beam experiment. The counter worked successfully, achieving a time resolution of 36 ps even at practical beam intensity 2x10^6 ions/s.3. The NA44 Collaboration which includes our group and the results obtained by these institutions were checked carefully.4. The results of pion interferometry in sulphur-lead collisions are to be published in near future as a paper in Nucl. Phys. B.5. Our preliminary results on kaon interferometry show that the source size of Kaons is smaller than that of pions by about a factor 1/2 for sulphur-lead collisions.6. No significant difference is found between the source sizes of K^+ and K^-.7. Any of singles spectra for pions, kaons, protons and anti-protons can be fitted by a single exponential function of the transverse mass of these hadrons and the temperature parameter of hadron source is deduced for these hadrons separately.8. A simulation code for lead-nucleus collisions has been developed.9. As one of central detectors of future lead-nucleus collisions, we are developing a gas Cherenkov counter for particle idenrification.