Metastable vacuum decay and $\theta$ dependence in gauge theory. Deformed QCD as a toy model

Abstract

We study a number of different ingredients related to the $\theta$ dependence, metastable excited vacuum states and other related subjects using a simplified version of QCD, the so-called "deformed QCD". This model is a weakly coupled gauge theory, which however preserves all the relevant essential elements allowing us to study hard and nontrivial features which are known to be present in real strongly coupled QCD. Our main focus in this work is to test the ideas related to the metastable vacuum states (which are known to be present in strongly coupled QCD in large $N$ limit) in a theoretically controllable manner using the "deformed QCD" as a toy model. We explicitly show how the metastable states emerge in the system, why their life time is large, and why these metastable states must be present in the system for the self-consistency of the entire picture of the QCD vacuum. We also speculate on possible relevance of the metastable vacuum states in explanation of the violation of local $\mathcal{P}$ and $\mathcal{C}\mathcal{P}$ symmetries in heavy ion collisions.

Version 2 updated to reflect version published in Nuclear Physics B

References in corpus (4)

• Charge separation induced by P-odd bubbles in QCD matter
• Center-stabilized Yang-Mills theory: confinement and large $N$ volume independence
• Exploring the structure of the quenched QCD vacuum with overlap fermions
• Long range order in gauge theories. Deformed QCD as a toy model

Cited by in corpus (7)

• $\theta$-dependence and center symmetry in Yang-Mills theories
• Oblique Confinement at $\theta \ne 0$ in weakly coupled gauge theories with deformations
• On the representation (in)dependence of $k$-strings in pure Yang-Mills theory via supersymmetry
• Metastable vacuum decay in center-stabilized Yang-Mills theory at large N
• Dynamical Casimir Effect in a small compact manifold for the Maxwell vacuum
• Resurgence and Dynamics of O(N) and Grassmannian Sigma Models
• The mixed $0$-form/$1$-form anomaly in Hilbert space: pouring new wine into old bottles