Quarks in cosmos and heavy ion collisions

点击翻译按钮获取中文摘要

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.