相对论非对称重离子碰撞中小相对动量区域2π干涉学

用小相对动量区域2π干涉学分析方法研究了相对论非对称重离子碰撞中π介子的吸收存在时对2π干涉学分析所得π源参数的影响,得到了不考虑和考虑π的吸收情况下所得到的源的参数的解析关系.与相对论非对称重离子碰撞1.8A GeVAr+Pb的实验结果进行了对比.     

计及多π关联效应的小相对动量区域2π干涉学

给出了相对论重离子碰撞中在关联nπ和非关联nπ的选取中存在多π关联效应时nπ关联函数的一般表达式.用这一表达式研究了计及多π关联效应的小相对动量区域2π干涉学,得到了从3π干涉学分析得到的π源参数与计及多π关联效应后,从2π干涉学分析得到的π源参数的解析关系,与相对论重离子中心碰撞1.?8A?GeV?Ar+?Pb的实验结果进行了对比.     

相对论重离子碰撞中集合流对2π干涉学分析的影响

用小相对动量区域2π干涉学分析方法研究了相对论重离子碰撞中集合流对2π干涉学分析的影响,给出了π源的表观半径与其真实半径的解析关系.     

超相对论重离子碰撞中小相对动量区域2π干涉学

用小相对动量区域π干涉学方法给出了超相对论重离子碰撞中两种模型下π源参数的关系,并与200A GeV O+Au碰撞的实验结果进行了对比.     

计及多π关联效应的小相对动量区载2π干涉学

给出了相对重离子碰撞中的在关联nπ和非关联nπ的选取中存在多π关联效应时nπ关联函数的一般表达式。用这一表达式研究了计及多π关联效应的小相对动量区域2π干涉学,得到了从3π干涉学分析得到的π源参数与计及多π关联效应后,从2π干涉学分析得到的π源参数的角析关系,与相以论重离子中心磁撞1.8A GeV Ar Pb的实验结果进行了对比。     

相对论重离子碰撞中小相对动量区域3π干涉学分析

用3π关联函数在小相对动量区域的幂级数展开,得到了3π关联函数与π源均方根半径的关系．对π源密度的高斯分布,在不考虑和考虑3π事件中的多π关联效应两种情况下,解析地得到了由2π干涉学分析得到的π源空间参数和由3π干涉学分析得到的π源空间参数的理论关系.计算了3π事件中的多π关联引起的2π关联因子的偏离.与小相对动量区域2π干涉学得到的结果和相对论重离子中心碰撞1.8A GeV Ar+Pb的实验结果进行了对比.     

多π关联对π发射源相干性的分析

对高能重离子碰撞中不同相于性程度π源产生的多π关联事件进行了蒙特卡罗模拟,比较了不同多重数子事件中的多π关联对π源相于性程度依赖的敏感性.对Bevalac流光室2.1A GeV Ne+Pb和1.2A GeV Ar+KCl中心碰撞产生的π源的相干性程度进行了分析,并与以往的2π干涉学的结果进行了比较.     

相对论重离子碰撞中π对相对动量分布

在π源动量分布的高斯分布下,给出了相对论重离子碰撞中非关联π对和关联π对的相对动量分布.用关联π对的相对动量分布得到球形高斯分布π源参数与椭球形高斯分布π源参数的解析关系,与相对论重离子中心碰撞1.8A GeV Ar+Pb的实验结果进行了对比.当π源温度更高时,应当用p₁(p)=N·exp(–m2+p2/T)进行计算.     

非静态球形夸克-胶子等离子体的2π干涉学的检测

提出了一种相对论重离子碰撞中强子物质生成时的π膨胀源模型. 得到了该模型中的小相对论动量区域的2π关联函数及表观π源参数R_a与实际π源参数R_e的关系. 这一关系与QGP生成时的关系有所区别. 这一区别可以用来检测相对论重离子碰撞中产生的非静态球形夸克-胶子等离子体的存在性. 两个关系也显示了一种标度行为.     

相对论重离子碰撞中π源密度分布和小相对动量区域2π干涉学分析

用2π关联函数在小相对动量区域的幂级数展开,得到了不同π源密度分布下源的空间参数、平均半径和均方根半径间关系,与相对论重离子中心碰撞1.8A GeV Ar+Pb的实验结果一致. 给出了上述反应中π源的平均半径和均方根半径.对不同的源密度分布,计算了K_t的值.     

Effect of the Choice of the Background on Two-Pion Inter-Ferometry

The effect of the choice of the background on the pion source parameters in two-Pion interferometry analyses in relativistic heavy-ion collisions is studied with the two-Pion interferometry at small relative momentum. The analytic relations between the pion source parameters from two-Pion interferometry analyses with different backgrounds are obtained, and comparison is made with the experimental measurements of the cental relativistic heavy-ion collisions of 1.8 A GeV Ar+Pb.     

Multiplicity dependence of the pion source in S+A collisions at the CERN SPS

The emission of pions from relativistic heavy-ion collisions of S+S, S+Ag and S+Pb at 200 GeV/nucleon is characterized using two-particle interferometry. The multiplicity dependence of the pion source parameters near midrapidity is studied. The transversal (R _t) and longitudinal (R _l) pion source parameters are independent of the initial nuclei in the interaction and increase with increasing multiplicity. This suggests that the freeze-out process is governed mainly by the particle multiplicity. The multiplicity dependence is weaker than that expected from a simple model of a freeze-out at a constant density.     

An Explanation of a Phenomenon in Relativistic Heavy-Ion Collisions

The multi-source pion interferometry in relativistic heavy-ion collisions is presented and two-source models for hadron gas and hadron gas plus quark-gluon plasma are proposed. The models can resolve the HBT puzzle. For the same $q$ and different direction of \bar{q}, the two-pion correlation functions show characteristic oscillation behaviors, which may be used to distinguish the two-source models. Our research also showes that the multi-source pion correlations can resolve the HBT puzzle.     

Determining pion source parameters in relativistic heavy-ion collisions

Two-pion inclusive spectra from relativistic heavy-ion collisions are related to single-particle inclusive measurements in a Lorentz-invariant formulation of the Hanbury-Brown-Twiss effect. A thermal pion source with a gaussian space-time distribution is assumed. The angular anisotropy and moments of the correlation function are computed to facilitate the determination of pion source parameters from the ratios of the two-pion to single-pion inclusive data.     

Two-pion interferometry at small relative momentum for pion sources with transverse and longitudinal expansions in relativistic heavy ion collisions

A two-pion correlation function at small relative momentum for pion sources with transverse and longitudinal expansions in relativistic heavy ion collisions is obtained using two-pion interferometry at small relative momentum, and the relations between the real and apparent parameters of the pion source are given. The relations can be used to extract both the temperature and the transverse and longitudinal expansion velocities of pion sources and to verify the correctness of relativistic transformation T′=T\sqrt {1-v^2} of temperature in relativistic statistical mechanics and thermodynamics.     

Three-pion correlations for studying partial coherence in nuclear collisions

Use of three-particle correlations provides a unique tool for studying partial coherence in relativistic heavy-ion collisions. Here a theory is presented for multiple coherent source components of partially coherent pion radiation. Results are given for the relative probabilities of emission of one, two, or three pions. The calculations on the relation between two- and three-pion correlators give some evidence, when compared with available experimental data, for the existence of partial coherence and multiple coherent components in heavy-ion collisions.     

Two-Pion Interferometry at Small Relative Momentum Taking Account for Multi-Pion Correlations

A general expression for nπ correlation function is given when there are multi-pion correlations in the choices of correlated nπ and uncorrelated nπ. Using this expression, the two-pion interferometry at small relative momentum which takes account for multi-pion correlations is studied, the relations between the pion source parameters from the two-pion interferometry and the three- pion interferometry are obtained analytically, and comparison is made with the experimental results of central relativistic heavy ion collisions 1.8 A GeV Ar+Pb.     

相对论重离子碰撞中部分相干源的相干因子

给出了两种统计系综下相对论重离子碰撞中部分相干源的相干因子的表达式     

Test of Quark-Gluon Plasma of Cylinder Shape by Two-Pion Interferometry

The two-pion correlation functions are different for some pion source distributions in two-pion interferometry.If quark-gluon plasma of cylindrical shape is produced in relativistic heavy ion collisions, the pion mesons will emit from the surface of quark-gluon plasma of cylindrical shape and the corresponding correlation function will have a special oscillation behavior. The oscillation behavior can be used to verify the existence of quark-gluon plasma and is also a signature of the appearance of quark-gluon plasma.