Connecting Parton Cascade to QCDS Shear Viscosity for a Dynamical Model of Finite Temperature Kinetic Theory

将 Parton Cascade 连接到 QCDS 剪切粘度以建立有限温度动力学理论的动态模型

• 批准号: 2310021
• 负责人: Zi-Wei Lin
• 金额: $ 27万
• 依托单位: East Carolina University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2310021&HistoricalAwards=false
• 关键词: Connecting; Parton; Cascade; QCDS; Shear

Experiments involving high-energy heavy-ion collisions at world-leading accelerator facilities such as the Relativistic Heavy Ion Collider (RHIC) in the U.S. and the Large Hadron Collider (LHC) in Europe, are being used to study the constitutive blocks of extreme states matter at high density and temperature. Such studies provide insights regarding the properties of the Universe right after the Big Bang, when elementary particles such as gluons and quarks formed a state of matter known as the quark gluon plasma (QGP) or quark soup. This project will support the development of theory, models and simulations needed to improve our understanding of the QGP formation and its dynamical properties. The project will also support the training of students at the graduate and undergraduate levels. Under the PI’s mentorship the students will acquire practical and analytical skills that will serve them well in their future careers in academia or industry. The computer codes developed by the PI and their students are open source and will provide a testbed for future research for the benefit of the nuclear physics community.The main goal of this project is to develop the current ZPC parton cascade, which solves the nonlinear relativistic Boltzmann equation, into a dynamical model of finite temperature QCD kinetic theory. Currently ZPC only includes elastic scatterings and treats all flavors with the same two-gluon scattering cross section. In addition, its cross section is determined by a fixed screening mass throughout the parton evolution; this leads to a decrease of the ZPC eta/s with temperature, contrary to the results from pQCD or the Bayesian analysis of available experimental data. Making the screening mass temperature-dependent will lead to the correct temperature-dependence of eta/s. Leading-order inelastic parton processes will be included to describe the chemical equilibration, and flavor-dependent cross sections will be used to properly describe the plasma equilibration. After a determination of the accurate relationship between eta and the parton cross sections, the PI will adjust the screening masses to enable the parton cascade to match the expected QCD shear viscosity including its temperature dependence down to the QCD phase transition temperature.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在世界领先的加速器设施中涉及高能重型离子碰撞的实验，例如美国的相对论重离子对撞机（RHIC）以及欧洲的大型强子对撞机（LHC），用于研究高密度和温度的极端物质物质块。这样的研究提供了有关大爆炸后宇宙特性的见解，当时胶子和夸克等基本颗粒形成了一种称为夸克gluon等离子体（QGP）或夸克汤的物质状态。该项目将支持我们对QGP形成及其动态特性的理解所需的理论，模型和模拟的发展。该项目还将支持研究生和本科级别的学生培训。在PI的心态下，学生将获得实践和分析技能，这些技能将在学术界或行业的未来职业中为他们提供良好的服务。 PI及其学生开发的计算机代码是开源的，将为未来的核物理界的研究提供测试床。该项目的主要目标是开发当前的ZPC Parton Cascade，该ZPC Parton Cascade解决了非线性相对性的玻尔兹曼方程，并将其作为一个有限温度QCD QCD Kinetic Theory的动态模型。目前，ZPC仅包括弹性散射，并以相同的两粘合散射横截面处理所有口味。此外，其横截面由整个Parton进化的固定筛选质量确定。这导致ZPC ETA/S随温度的降低，与PQCD或可用实验数据的贝叶斯分析形成鲜明对比。使筛选质量依赖性依赖性将导致ETA/S的正确温度依赖性。将包括领先的非弹性parton过程来描述化学平衡，并将使用依赖风味的横截面来正确描述等离子体平衡。在确定了ETA与Parton横截面之间的准确性关系之后，PI将调整筛选质量，使Parton Cascade能够与预期的QCD剪切粘度匹配，包括其温度依赖性降低了其对QCD相过渡温度的依赖。该奖项通过评估了NSF的法定任务，反映了NSF的法定任务，并通过评估了CRACTIAL IDICTIAL IDICTIAL和BRODITIAL IDICAIL和BRODITIAL和BRODITIAL IDICAIL和BRODITIAL和BRODITIAL。