Using a multi-phase transport model（AMPT） that includes both initial partonic and hadronic interactions, we study neighboring bin multiplicity correlations as a function of pseudorapidity in Au＋Au collisions at √sNN= 7.7- 62.4 GeV.It is observed that for √sNN〈19.6 GeV Au＋Au collisions, the short-range correlations of final particles have a trough at central pseudorapidity, while for √sNN 〉19.6 GeV AuAu collisions,the short-range correlations of final particles have a peak at central pseudorapidity. Our findings indicate that the pseudorapidity dependence of short-range correlations should contain some new physical information, and are not a simple result of the pseudorapidity distribution of final particles. The AMPT results with and without hadronic scattering are compared. It is found that hadron scattering can only increase the short-range correlations to some level, but is not responsible for the different correlation shapes for different energies. Further study shows that the different pseudorapidity dependence of short-range correlations are mainly due to partonic evolution and the following hadronization scheme.
We present a systematic analysis of two-pion interferometry for the central Au＋Au collisions at √SNN=3, 5, 7, 11, 17, 27, 39, 62, 130 and 200 GeV/c with the help of a multiphase transport （AMPT） model. Emission source-size radius parameters Rlong, Rout, Rside and the chaotic parameter A are extracted and compared with the experimental data. Transverse momentum and azimuthal angle dependencies of the HBT radii are also discussed for central Au＋Au collisions at 200 GeV/c. The results show that the HBT radii in central collisions do not change much above 7 GeV/c. For central collisions at 200 GeV/c, the radii decrease with the increasing of transverse momentum PT but are not sensitive to the azimuthal angle. These results provide a theoretical reference for the energy scan program of the RHIC-STAR experiment.
在相对论重离子碰撞中,整体喷注作为研究解禁闭的夸克胶子等离子体的重要探针近年来已被广泛研究。本工作基于多相输运模型(A Multi-Phase Transport model,AMPT),研究了在质心系能量为2.76 TeV的铅核-铅核碰撞中的双喷注不对称、喷注的碎裂函数和喷注形状三方面的内容。数值模拟结果表明,在喷注与部分子物质的强相互作用中,喷注会有明显的能量损失。末态双喷注不对称是由初态不对称度和部分子喷注能损的共同作用导致的;喷注的碎裂函数可以分解为碎裂强子化和组合强子化两部分;相比于领头喷注,由于次领头喷注能量损失更大,所以导致次领头喷注的形状改变更大一些。
