整体喷注的输运模型研究  

Full jet in a multi-phase transport model

作　　者：聂茂武 马国亮[1] 

机构地区：[1]中国科学院上海应用物理研究所,嘉定园区上海201800 [2]中国科学院大学,北京100049

出　　处：《核技术》2014年第10期99-104,共6页Nuclear Techniques

基　　金：973计划(No.2014CB845404);国家自然科学基金(No.11175232、No.11035009、No.11375251)资助

摘　　要：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。Background： Jet, produced by initial quantum chromodynamics QCD hard scatterings, is one of the important probes to study the properties of strongly-interacting matter because it interacts with the QCD medium and loses its energy when it passes through the QCD medium. Purpose： To understand the mechanism of jet quenching, a complementary study on fully reconstructed jet is essential. Methods： In this work, a multiphase transport model is utilized to study the dijet asymmetry, jet fragmentation function and jet shape. Results： The A Multi-Phase Transport model （AMPT） simulation results can basically describe the experimental data. Jet loses energy significantly for strong interactions between jets and partonic matter. Conclusion： Final dijet asymmetry is driven by both initial dijet asymmetry and partonic jet energy loss. Jet fragmentation function can be decomposed into fragmentation and coalescence parts. Compared with leading jet, the subleading jet shows a larger medium modification for its shapes, especially in central Pb＋Pb collisions with a larger dijet asymmetry.

关 键 词：重离子碰撞 多相输运模型 整体喷注 碎裂函数 喷注形状 

分 类 号：TL99[核科学技术—核技术及应用]