  Pseudoscalar correlator is measured in a singular (monopole dominant) and a
regular (photon dominant) parts of a maximal abelian field on SU(2) lattice. In
the abelian field and its singular part, light pseudoscalar boson are observed
similar to that in SU(2) field. On the other hand , the correlator in the
regular part behaves like a product of free quark and anti-quark. Obtained
results give a support for a possibility that monopole condensation is
responsible for chiral symmetry breaking as well as confinement. Correlation
between monopoles and instantons is also investigated by observing topological
charge. A field including monopoles carrys topological charge with good
correlation to that in original SU(2) gauge field while that including only
photons shows no topological charge.
