Parity-odd domain structure with generalized θ vacuum

Recent experiments in heavy ion collisions have shown the possibility of creating parity-odd domains resulting from the θ term in the strong interaction Lagrangian. The θ term originates from the nontrivial solution for the quantum chromodynamic (QCD) vacuum known as the θ vacuum, and the value of θ 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 θ 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 the dimension-2 condensate.