LHC能区大角辐射物理机制研究

The latest results from LHC indicate the large angle radiation is significantly when partons go through hot-dense QCD matter. Based on the JEWEL model, the applicant will develop and build RM-JEWEL(Renzhuo Modified Jet Evolution With Energy Loss) package by implement of large angle radiation mechanism, the modification of partion evolution models DGLAP and Sudakov form factor, as well as the two hadronisation models of Lund string and the local parton hadron duality. RM-JEWEL devoted to systematical study the large angle gluon radiation caused by the small angle radiation the mutiple parton interaction, radiated with relative large angle directly by the initial partons collisions, and the coexist-competing of quantum coherence and decoherence. It's also used to extract the pion^{0}-hadron correlation pattern and thus offers a flexible way to study the influence of final hadron spectrum, nuclear modification factor and jet suppression, the double peaks phenomena from the away side in azimuthal measurement and the flow effect by the large angle radiation. The proposal could improve the understanding that how the partons interact with QCD matter.

LHC能区最新数据表明部分子在穿越致密QCD物质中大角辐射迹象显著。本项目基于JEWEL模型，补充大角辐射机理，修改部分子演化动力学模型DGLAP和Sudakov形式因子，运用Lund弦碎裂机制和部分子强子双重性假设，发展和建立RM-JEWEL（Renzhuo Modified Jet Evolution With Energy Loss)唯象模型。理论上系统研究由于小角辐射胶子在多重部分子作用下造成的大角偏转、初始部分子碰撞直接导致的大角辐射以及量子相干与退相干效应等对大角辐射的贡献，并应用于pion^{0}-强子关联研究，灵活分析大角辐射机制射对末态强子谱、核修正因子和喷注压低因子，轴向远离端双峰现象和集体流等影响。从而揭示部分子与致密QCD物质相互作用机理。

项目跟进LHC最新实验结果和理论进展，研究了来自大角辐射不同物理机制的贡献，将代码修改为python源码；唯象上采用了随机改变胶子辐射角度从而差异化不同物理机制的贡献，研究了大角辐射对双喷注能量反对称分布，以及对喷注结构的影响；唯象上研究了LHC能区不同碰撞系统在不同碰撞能量下喷注拓扑结构和喷注形状的变化规律，提出了喷注微分粒度的概念；理论上上采用玻尔兹曼动力学和郎之万动力学研究重味夸克在致密QGP中输运系数对温度和能量的依赖关系；此外超出原研究计划，探索研究了人工智能方法学习胶子辐射规律。在项目执行期间，发表SCI论文3篇（包含两篇近期接收，已挂arXiv网站，预期2019年四、五月份见刊），近期完成两篇SCI论文SCI待投，预期2019年下半年可以见刊。