400GeV/cpp碰撞中的多粒子关联、阶乘累积矩和关联积分

利用CERN NA27合作组提供的LEBC泡室照片,测量了400GeV/c pp碰撞产生的带电粒子赝快度分布.计算了标度阶乘累积矩K_q,与具有同样单粒子谱但是没有关联的蒙特卡罗事例得到的结果相比较,表明对于宽的混合多重数分布,K₂的一个显著部分是由于多重数涨落引起单粒子密度涨落造成的.利用星形关联积分法计算得到的阶乘累积矩,显著地降低了高阶阶乘累积矩的统计误差,但基本结论保持不变.     

400GeV/c pp碰撞时两粒子赝快度关联

利用LEBC泡室照片对400GeV/c pp碰撞产生的带电粒子赝快度分布进行了测量.研究了固定多重数时的两粒子赝快度关联.用结团模型对实验数据进行了拟合,得到的结团平均大小以及结团的衰变宽度随带电粒子多重数的变化不大.     

400GeV/c pp碰撞连续阶数阶乘矩和多重分形分析

对华家照提出的F_q矩的矩阶数连续化方案进行了检验,发现它不能用于真实数据的分析,对此作了改进,使它能用于真实的实验数据的分析,对400GeV/c pp碰撞产生的带电粒子赝快度分布实验数据的分析结果表明,阶乘矩的矩阶数连续崐化方法是可行的,说明在400GeV/c pp碰撞多重产生过程中可能存在多重分形行为.     

400GeV/c pp碰撞前后多重数关联

利用LEBC泡室照片,对400GeV/c pp碰撞产生的带电粒子赝快度分布进行了测量.得到了固定总多重数时前向半球的多重数分布;计算了全相空间、赝快度中心区以及中心区以外的前后多重数关联强度;得到了关联强度随赝快度窗口的变化图.用结团模型分析了前后关联的实验数据,结果表明,结团的平均大小与是否考虑领头粒子效应有关.     

阶乘累积矩与阶乘矩之比随相空间大小的变化

利用400GeV/cpp碰撞多重产生的实验数据计算了不同赝快度窗口时多重数分布的阶乘累积矩与阶乘矩之比.结果表明,随着阶数q的增加,比值H_q首先迅速下降,然后在零附近振荡.这与PQCD的预言是一致的.不同的是第一极小值的位置在赝快度窗口变小时移向较高的级数.     

400GeV/c pp碰撞两粒子关联的角度依赖性

利用400GeV/c pp碰撞多重产生的实验数据计算了粒子-粒子关联(PPC)及其不对称性(PPCA)的角度依赖性.结果与L3的e⁺e^－数据有明显的差别,但与NA22强子碰撞的实验数据符合得很好;领头粒子对强子碰撞的PPCA分布有很大影响.通过计算两粒子方位角差的分布观察到了方位角关联.     

400GeV/c pp碰撞中的非热相跃迁

利用CERNNA27合作组提供的LEBC泡室照片测量了400GeV/c pp碰撞产生的带电粒子赝快度分布.利用星形积分法计算标度阶乘矩F_q直至q=7.分析结果表明可能存在非热相跃迁和两种不同的多粒子产生方式.观察到涨落的多重分形结构支持粒子产生的随机级联模型.     

400GeV/c pp碰撞间歇指数的测量

利用CERNNA27合作组提供的LEBC泡室照片对400GeV/c pp碰撞产生的带电粒子赝快度分布进行了测量.计算了标度阶乘矩.得出间歇指数随矩阶数的增加而增加,随平均多重数的增加而变小;反常分形维数dq随q的增加而增加.这表明在强子-强子碰撞中多粒子产生具有自相似级联的性质.     

400GeV/c pp碰撞赝快度分布涨落的分形分析

利用改进的多重分形矩分析了400GeV/c pp碰撞多重产生的分形行为.计算了广义维数D_q(q=2—5),并与由标度阶乘矩方法得到的结果作了比较.结果表明观察到了多重分形特征.对Fujio Takagi提出的分形分析方法作了探讨.     

400GeV/c pp碰撞半单举带电粒子赝快度分布测量

利用CERN NA27合作组提供的LEBC泡室照片,测量了400GeV/c pp碰撞产生的带电粒子多重数为8—12的赝快度分布,并用结团模型分析了在固定总多重数时质心系前向半球的多重数分布.结果表明结团的平均大小与是否考虑领头粒子效应有关.     

System size and energy dependence of jet-induced hadron pair correlation shapes in Cu+Cu and Au+Au collisions at square root sNN=200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at square root sNN=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.     

Two-particle Pseudorapidity Correlations in pp Collisions at 400GeV/c

The pseudorapidity distributions of charged produced in pp collisions at 400GeV/c have been measured using LEBC films.Two-particle pseudorapidity correlations at fixed multiplicity have been studied.The experimental data was fitted by cluster model.It is found that the average cluster multiplicities as well as the cluster decay widths both vary slightly with charged multiplicity.     

400GeV/c pp碰撞产生粒子的方位角结构

利用不同的方法对400GeV/c pp碰撞多重产生的方位角结构进行了研究.一维和二维标度阶乘矩的分析结果表明两维时的间歇效应较强,这与“喷注形”多粒子产生机制是不矛盾的. 但由其它方法分析结果表明方位角结构似乎具有随机的性质,没有“喷注形”多重产生机制的证据.     

Multiplicity dependence of intermittency in one and two dimensions in proton-nucleus interactions at 800 GeV

The intermittency effect has been observed in interactions of 800 GeV protons with emulsion-nuclei in one-(pseudorapidity/azimuthal angle) and two-dimensional (pseudorapidity and azimuthal angle) phase spaces in different multiplicity intervals. The intermittency strength is found to decrease with increasing multiplicity. Compared to one dimension, the two dimensional distribution is found to reflect better the intermittent behavior of the interactions. The dependence of various intermittency parameters on order of moment gives clear evidence of self-similar cascade mechanism in the interactions but there is no definite indication of the presence of different phases in the cascade.     

Charged-particle multiplicity near midrapidity in central Au+Au collisions at sqrt[SNN]=56 and 130 GeV

We present the first measurement of pseudorapidity densities of primary charged particles near midrapidity in Au+Au collisions at sqrt[s(NN)] = 56 and 130 GeV. For the most central collisions, we find the charged-particle pseudorapidity density to be dN/deta|(|eta|<1) = 408+/-12(stat)+/-30(syst) at 56 GeV and 555+/-12(stat)+/-35(syst) at 130 GeV, values that are higher than any previously observed in nuclear collisions. Compared to proton-antiproton collisions, our data show an increase in the pseudorapidity density per participant by more than 40% at the higher energy.     

Production of Ring-like Events in pp Collisions at 400GeV/c

The production mechanism of ring-like events has been investigated by using the data of pseudorapidity distribution of charged particles produced in pp collisions at 400GeV/c. The results show that the model of coherent gluon emission within a finite region of space-time is a possible production mechanism of ring-like events, but certainly not dominant.