  Charge separation induced by the chiral magnetic effect suggested that some
${\cal P}$- or ${\cal CP}$-odd metastable domains could be produced in a QCD
vacuum in the early stage of relativistic heavy-ion collisions. Based on a
multi-phase transport model, our results suggest that a domain-based scenario
with final state interactions can describe the solenoidal tracker at RHIC
detector (STAR) measurements of both same- and opposite-charge azimuthal angle
correlations, $<\cos(\phi_{\alpha}+\phi_{\beta})>$, in Au+Au collisions at
$\sqrt{s_{_{\rm NN}}}=200$ GeV. The occupancy factor of the total volume of
domains over the fireball volume is small, which indicates that the size and
number of metastable domains should be relatively small in the early stage of a
quark-gluon plasma.
