Theoretical study of beauy-ins collisions at exirame high enngiro

Exirame High Enngiro 的 Beauy-ins 碰撞理论研究

基本信息

批准号：
06640394
负责人：
MATSUI Tetsuo
金额：
$ 1.34万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

We conducted a theoretical research on the expected properties of dense matter produced in ultra-relativistic heavy ion collisions and their experimental probes. Progress has been made in the following problems :1) Shadowing effects in pion interferometry : It is well known that the momentum correlation between a pair of identical particles produced in high energy collisions can be used to extract information on trhe space-time geometry of the particle source. We studied how such correlation is affected by the final state interaction between the pions and the pions source itself. It was found that if the pions are emitted from a strong souce, such as a quark-gluon-plasma, the source acts as a strong absorber of pions and this may result in suppression of the momentum correlations at small relative momenta of pions.2) Chiral phase transition at finite temperature in the linerar sigma model : We studied the chiral phase transition in equilibrium using the linear sigma model in a self-consistent Hartree approximation. Previous works had encountered difficulties of violating Goldstone's theorem in the chiral limit. We formulated a new self-consistent approximation scheme which respects the Goldstone theorem explicitly. It was shown that in this approximation the theory predicts a (weak) first order phase transition in the chiral limit due to the long range fluctuations of meson field whose effective masses become small in the transition region.3) Variational approach for dynamics of expanding quantum fields : We descibed the dynamics of expanding quantum fields in terms of variational wave functional in the functional Schrodinger picture. The variational wavefunctional is chosen in a generalized gaussian form, as for the free field. We constructed a family of boost in variant solutions to the equations of motion derived by the variational principle.

我们对超相对论重离子碰撞产生的致密物质的预期性质及其实验探针进行了理论研究。在以下问题上取得了进展：1）π介子干涉测量中的阴影效应：众所周知，高能碰撞中产生的一对相同粒子之间的动量相关性可用于提取有关粒子时空几何形状的信息。粒子源。我们研究了π介子和介子源本身之间的最终状态相互作用如何影响这种相关性。研究发现，如果π介子是从强源（例如夸克-胶子-等离子体）发射的，则该源将充当介子的强吸收体，这可能会导致在介子相对动量较小时抑制动量相关性2。 ) 线性 sigma 模型中有限温度下的手性相变：我们使用自洽 Hartree 近似中的线性 sigma 模型研究了平衡状态下的手性相变。以前的工作在手性极限方面遇到了违反戈德斯通定理的困难。我们制定了一个新的自洽近似方案，明确尊重戈德斯通定理。结果表明，在该近似中，由于介子场的长程涨落，其有效质量在过渡区变小，该理论预测了手性极限内的（弱）一级相变。 3）扩展量子动力学的变分方法场：我们用泛函薛定谔图中的变分波泛函描述了扩展量子场的动力学。对于自由场，变分波函数被选择为广义高斯形式。我们构建了一系列由变分原理导出的运动方程的变体解。