Quarks in cosmos and heavy ion collisions

宇宙中的夸克和重离子碰撞

• 批准号: SAPIN-2019-00033
• 负责人: Zhitnitsky, Ariel
• 金额: $ 6.92万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739415
• 关键词: Quarks; cosmos; heavy; ion; collisions

There are fundamental links between cosmology and particle physics, which have been well established at all scales. In particular, the physics of the early Universe, baryogenesis, cosmological nucleosynthesis are based on our modern understanding of particle physics. The goal of the project is the study of QCD in the unusual environment when temperature T, chemical potential and the so-called theta parameter are non-zero. It is generally accepted that the theta parameter was not zero during the QCD epoch in early Universe. It is assumed that the theta parameter relaxes to zero as a result of the dynamics of the axion field, which was postulated 40 years ago to resolve the so-called strong CP problem. The main objective of the proposal is to study a variety of different physics effects related to the dynamics of the axion field during the QCD transition. There are few themes in the project which are inherently related: 1. The analysis in a simplified version of QCD, the so-called ``deformed QCD" which however preserves all the relevant elements of strongly coupled QCD such as confinement, degeneracy of topological sectors, nontrivial theta dependence, and many other important aspects which allow us to test some fascinating features of strongly interacting QCD. 2. Application of these fundamentally new ideas to heavy ion collisions, astrophysics and cosmology. In particular, I am closely collaborating with senior astrophysics people and particle physics experimentalists to test a proposal that the dark matter problem and baryogenesis problem are inherently linked  to each other and should be solved simultaneously as the observed dark matter density and the observed baryon density are very similar in magnitudes. If these components are originated from different physics they must be drastically different, in contrast with present observations. The key element in this proposal is the presence of non-vanishing CP-odd parameter theta which generates the observed asymmetry between matter and antimatter in the Universe as a result of the so-called charge separation effect. This proposal gives very specific and unique predictions which can be tested by a number of existing and upgraded instruments such as upgraded CAST (CERN Axion Search Telescope).  3.The third part of my project is based on the observation that very subtle elements of the theoretical construction from item 1 could be tested in a table top experiment. The measuring of the so-called Topological Casimir Effect (TCE) may shed some light on the nature of the so-called vacuum energy. Similar table top experiment could be designed to be sensitive to the theta parameter itself in the Maxwell Theory. The suggested idea on measuring of the TCE is very different from all previous proposals which are sensitive to the derivatives of theta, but not to theta parameter itself.

宇宙学和粒子物理学之间有着根本的联系，这在所有尺度上都已经得到了很好的建立。特别是，早期宇宙的物理学，重子生成，宇宙核合成是基于我们对粒子物理学的现代理解。该项目的目标是研究在温度T、化学势和所谓的θ参数不为零的异常环境中的QCD。一般认为，在早期宇宙的QCD时期，θ参数不为零。假设θ参数由于轴子场的动力学而松弛到零，这是40年前为了解决所谓的强CP问题而假设的。该计划的主要目标是研究QCD跃迁过程中与轴子场动力学相关的各种不同的物理效应。该项目中有几个本质上相关的主题：1。在简化的QCD中的分析，即所谓的"变形QCD”，它保留了强耦合QCD的所有相关元素，如禁闭，拓扑扇区的简并性，非平凡的θ依赖性，以及许多其他重要方面，使我们能够测试强相互作用QCD的一些迷人的特征。 2.将这些全新的想法应用于重离子碰撞、天体物理学和宇宙学。特别是，我正在与高级天体物理学家和粒子物理实验学家密切合作，以测试一个提议，即暗物质问题和重子生成问题本质上是相互联系的，应该同时解决，因为观测到的暗物质密度和观测到的重子密度在量级上非常相似。如果这些成分来自不同的物理学，那么它们与目前的观测结果相比，一定是截然不同的。这个提议的关键要素是存在非零CP奇参数θ，它产生了宇宙中物质和反物质之间观察到的不对称性，这是所谓的电荷分离效应的结果。这个建议给出了非常具体和独特的预测，可以通过一些现有的和升级的仪器，如升级的CAST（CERN Axion Search Telescope）进行测试。3.我的项目的第三部分是基于观察，从项目1的理论结构中非常微妙的元素可以在桌面实验中进行测试。对所谓的拓扑卡西米尔效应（TCE）的测量可能会对所谓的真空能量的性质有所帮助。类似的桌面实验可以设计成对麦克斯韦理论中的θ参数本身敏感。所提出的关于测量TCE的想法与所有先前的建议非常不同，这些建议对θ的导数敏感，但对θ参数本身不敏感。