  We promote the usual QCD $\theta$-parameter to a field and interpret it as
the phase of the quark condensate, which becomes nontrivial when topological
defects, vortices in our formulation, are induced in the quark condensate by
the QCD strings (chromoelectric flux tubes). The QCD topological term emerges
naturally as a derivative coupling between the Chern-Simons current and a
supercurrent in the quark condensate. This new formulation can address the
$U_A(1)$ problem and leads to the chiral magnetic effects. It is possible that
in this formulation the strong CP problem can be avoided without the axion
particle.

High Energy Physics - Phenomenology