  It has been known that when a charged fermion scatters off a monopole, the
fermion in the $s$-wave component must flip its chirality, i.e., fermion number
violation must happen. This fact has led to a puzzle; if there are two or more
flavors of massless fermions, any superposition of the fermion states cannot be
the final state of the $s$-wave scattering as it is forbidden by conservation
of the electric and flavor charges. The unitary evolution of the state vector,
on the other hand, requires some interpretation of the final states. We solve
the puzzle by finding new particle excitations in the monopole background,
where multi-fermion operators exhibit condensation. The particles are described
as excitations of closed-string configurations of the condensates.
