Chiral Symmetry Breaking by Monopole Condensation

Under the assumption of Abelian dominance in QCD, we show that either color charge or chirality of quark is not conserved, when the low energy massless quark collides with QCD monopole. Because the color charge is conserved in reality, the chirality is not conserved. We show by using chiral anomaly that chiral non symmetric quark pair production takes place when a classical color charge is putted in a vacuum with monopole condensation, while chiral symmetric pair production takes place in a vacuum with no monopole condensation. Our results indicate that the chiral symmetry is broken by the monopole condensation.