α模型中不固定多重数下的阶乘矩、粒子数关联矩

利用二维相空间自仿射分形的随机级联α模型,采用蒙特卡罗模拟的方法,研究了阶乘矩､粒子数关联矩在不固定多重数下,对应于多重数相对起伏强度n_f的依赖关系,得到:阶乘矩、粒子数关联矩依赖于多重数相对起伏n_f,但间歇指数一般不依赖于n_f,当n_f较小时这种依赖性得以消除.     

A study of the dynamical-fluctuation property inside jets in e+e- collisions

A study of the dynamical-fluctuation property of 2-jet events is carried out. It is found that the dynamical fluctuations of the hadronic system inside 2-jet events change with the variation of the cut parameter ycut. There is a transition point, where the dynamical fluctuations in these systems are circular in the transverse plane; and are elliptical in the longitudinal-transverse planes. It is shown that this transition point corresponds to the scale of visible jets. Meanwhile, the dynamical fluctuation properties inside a single-jet in 2-jet and 3-jet events are compared. The dynamical fluctuations inside quark- and gluon-jets are found to be qualitatively different. A scale for the "visible gluon jet" production is thus obtained.     

相对论重离子碰撞中强子气体膨胀过程的蒙特卡罗研究

利用AMPT蒙特卡罗产生器中的强子化程序模块ART1.0, 得到了强子化过程的演化图形, 并基于强子在不同时刻的空间分布图, 估算出了不同时刻的反应区域半径. 将所得结果与根据HBT关联得到的结果相比较, 定出了冻结为强子气体的时刻, 得到了合理的结果.     

对高能碰撞未态粒子的阶乘矩拟合修正曲线的方法

高能碰撞末态粒子在相空间的动力学分布存在着非均匀因素的影响,通过对这种非均匀因素影响的研究,引入了修正系数,和到了拟事修正曲线的判据,给出了计算修正系数的方法。     

LHC高能Pb—Pb和Ca—Ca碰撞中的直接硬光生J/ψ及γ(English)

研究了LHC中,Pb－Pb以质心系能量5．5ATeV以及Ca-Ca以质心系能量7ATeV碰撞过程中的硬直接光生J／ψ和γ过程：A＋A-A＋J／ψ（γ）＋X．结果表明该过程不仅可用于测量原子核中的胶子分布,还可以用以研究大R_t胶子以及重夸克的J／ψ碎裂机制．     

用阶乘矩技术提高相对论重离子碰撞实验数据样本中QGP事件比例的方法

在相对论重离子碰撞中形成QGP时,与之相伴随的有一些非QGP背景事件.把末态(方位角、快度)二维相空间中阶乘矩剧烈上翘的消失与一些普遍认为的QGP信号(如K/π比的上升)联系起来讨论,提出了一种从实验数据中挑选候选的QGP事件的方法.用Mont–Carlo模拟表明,这种方法有效地提高了挑选出来的子样本中QGP事件的信噪比.     

Trace initial interaction from final state observable in relativistic heavy ion collisions

In order to trace azimuthal angle dependence of the initial interaction in ultra-relativistic heavy ion collision, two azimuthal multiplicity-correlation patterns neighboring and fixed-to-arbitrary angularbin correlation patterns -- are suggested. From the simulation of Au ＋ Au collisions at √SNN = 200 GeV by using the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without string melting, we observe that the correlation patterns change gradually from out-of-plane preferential one to inplane preferential one when the centrality of collision shifts from the central collision to peripheral collision, meanwhile the anisotropic collective flow v2 keeps positive in all cases. This regularity is found to be collision energy independent. The physics behind the two opposite trends of correlation patterns, in particular, the presence of out-of-plane correlation patterns at RHIC energy, are discussed.     

Critical phenomena in a disc-percolation model and their application to relativistic heavy ion collisions

By studying the critical phenomena in continuum-percolation of discs, we find a new approach to locate the critical point, i.e. using the inflection point of P∞ as an evaluation of the percolation threshold. The susceptibility, defined as the derivative of P∞, possesses a finite-size scaling property, where the scaling exponent is the reciprocal of v, the critical exponent of the correlation length. A possible application of this approach to the study of the critical phenomena in relativistic heavy ion collisions is discussed. The critical point for deconfinement can be extracted by the inflection point of PQGP -- the probability for the event with QGP formation. The finite-size scaling of its derivative can give the critical exponent v, which is a rare case that can provide an experimental measure of a critical exponent in heavy ion collisions.     

在电子-质子碰撞中识别瞬子末态方法的蒙特卡罗研究

在e⁺p深度非弹性散射的光子胶子融合过程中有可能出现瞬子. 这是 一类特殊的事件, 称为瞬子参与的深度非弹性散射事件. 本文用蒙特卡罗事件产生器QCDINS讨论了在瞬子参与的深度非弹性散射事件中识别瞬子末态和流喷注的方法. 对各种不同方法作了对比研究. 找到了一种能使重建得到的喷注能量、瞬子能量、瞬子质量与强子化前的取值均比较接近的最佳方法.     

LHC光生过程中的核遮蔽效应

给出了关于LHC实光子核遮蔽效应的一些结果.证明了遮蔽随光子能量Er的增加而变强.给出了反应过程γ+A→V+A中的ρ,ω,φ总截面对质心系能量的依赖性.结果表明,存在一个能量的临界点,在该点以上的核遮蔽强到足可以被测到.