Space-Time Evolution of Hot Hadronic Matter Studied in PHENIX

PHENIX 研究的热强子物质的时空演化

• 批准号: 12440066
• 负责人: SUGITATE Toru
• 金额: $ 8.7万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12440066/
• 关键词: high-energy heavy-ion collision; hadronic matter; space-time evolution; PHENIX experiment; Quantum interferometry; Lead Tungustate crystal; photon detector; PWO crystal; 鉛タングステン結晶

In order to investigate non-perturbative QCD phenomenon of multiple quarks at high temperature, we have carried out this study in cooperation with the PHENIX collaboration at BNL-RHIC. Very high-statistic data of more than 100 million events in gold on gold-nuclear collisions were successfully taken in 2000 to 2002. Spatial and temporal evolution of the hot and dense nuclear matter created during the collisions was studied through three-dimensional two-particle correlation functions of charged pion-pairs and kaon-pairs. We found very clear dependences of the source size parameters both on the impact parameter of primary nuclear collisions and on the momentum of observed pairs. It is concluded that a hydro-dynamical expansion is created inside the colliding section and the strong radial flow affects the momentum correlation of secondary particles at freeze-out, as we have seen in studies at the CERN-SPS energies. Long duration time of particle emission was not observed in the measurements of pions, and this fact turns out to exclude several models predicting longer duration time as the pair momentum increases. A new theoretical scenario is demanded to understand what's going on.An electro-magnetic calorimeter prototype composed of a 3 by 3 tower of lead-tungstate crystal (PWO) produced by Furukawa, was studied with photon beams at LNS, Tohoku University. It achieved the energy resolution of 32MeV for GeV photons. To develop a new photon detection system being replaced with aphotomultiplier tube, a readout system of an avalanche-photo-diode with a newly designed pre-amplifier was studied. We are now ready to build a proof model.As an extension of this study, we have submitted a new plan supposed by a Grants-in-Aid entitled "QCD matter at High-Temperature" starting in H15.

为了研究高温下多夸克的非微扰QCD现象，我们与BNL-RHIC的PHENIX合作组合作开展了这项研究。在2000年至2002年期间，成功地获得了超过1亿次金-核碰撞事件的非常高统计数据。通过带电π介子对和K介子对的三维两粒子关联函数，研究了碰撞过程中产生的热而致密的核物质的时空演化。我们发现非常清楚的依赖性的源的大小参数上的影响参数的初级核碰撞和观测对的动量。得出的结论是，流体动力学膨胀内的碰撞部分和强大的径向流影响的动量相关的二次粒子在冻结，我们已经看到在CERN-SPS能量的研究。在π介子的测量中没有观察到粒子发射的长持续时间，这一事实排除了几个预测随着对动量增加持续时间更长的模型。需要一个新的理论场景来理解正在发生的事情。东北大学LNS用光子束研究了由古河生产的3 x 3钨酸铅晶体（PWO）塔组成的电磁量热计原型。它实现了32 MeV的能量分辨率为GeV的光子。为了发展一种能取代光电倍增管的新型光子探测系统，研究了一种采用新型前置放大器的雪崩光电二极管读出系统。我们现在准备建立一个证明模型，作为本研究的延伸，我们已经提交了一个新的计划，由一个补助金设想的题为“QCD物质在高温下”开始在H15。

项目成果

I.G.Bearden: "Two-kaon correlations in central Pb + Pb collisions at 158 A GeV/c"Physical Review Letters. 87. 112301-1-112301-6 (2001)

I.G.Bearden：“158 A GeV/c 中心 Pb Pb 碰撞中的双 kaon 相关性”物理评论快报。

K.Adcox: "Flow Measurements via Two-Particle Azimuthal Correlations in Au + Au Collisions at √<SNN>=130 GeV"Physical Review Letters. 66. 212301-1-212301-6 (2002)

K.Adcox：“在 √<SNN>=130 GeV 处通过 Au + Au 碰撞中的两粒子方位相关进行流量测量”物理评论快报 66。212301-1-212301-6 (2002)

K.Adcox: "Centrality Dependence of Charged Particle Multiplicity in Au-Au Collisions at 【square root】s_<NN>=130 GeV"Physical Review Letters. 86. 3500-3505 (2001)

K.Adcox：“【平方根】s_<NN>=130 GeV 时 Au-Au 碰撞中带电粒子多重性的中心依赖性”物理评论快报 86. 3500-3505 (2001)。

TORU SUGITATE: "XXXI International Symposium on Multiparticle Dynamics"CORRELATIONS AND FLUCTUATIONS AT RHIC. 331-334 (2002)

TORU SUGITATE：“第三十一届多粒子动力学国际研讨会”RHIC 的相关性和波动。

K.Adcox: "Net Charge Fluctuations in Au+Au Interactions at 【square root】s_<NN>=130 GeV"Physical Review Letters. 89. 082301-1-082301-6 (2002)

K.Adcox：“【平方根】s_<NN>=130 GeV 时 Au+Au 相互作用的净电荷波动”物理评论快报 89. 082301-1-082301-6 (2002)