Parity Odd Domain Structure with Generalized $\theta$ Vacuum

TL;DR

This paper proposes a new method to generalize the QCD $ heta$ vacuum by using dimension 2 condensates, aiming to better understand the structure of parity-odd domains observed in heavy ion collisions.

Contribution

It introduces a novel approach to define the $ heta$ vacuum through gauge slices based on dimension 2 condensates, extending the theoretical framework of parity-odd domains.

Findings

A method to generalize the $ heta$ vacuum using dimension 2 condensates.

Calculation of parity-odd domain structures as unions of gauge slices.

Provides a new perspective on the $ heta$ vacuum in QCD.

Abstract

Recent experiments in heavy ion collisions have shown the possibility of creating parity-odd domains resulting from the $\theta$ term in strong interaction Lagrangian. The $\theta$ term originates from the nontrivial solution of QCD vacuum known as the $\theta$ vacuum, and the value of $\theta$ is taken to be a function of spacetime coordinates in the parity-odd domains. This means that we have to consider different theories at each point so that we need to devise a new approach to define the QCD vacuum. In this Letter, we suggest a method to generalize the $\theta$ vacuum by exploiting the dimension 2 condensates and to calculate the parity-odd domain structure as the union of gauge slices defined by the constant value of dimension 2 condensate.