  We show that local/semilocal strings in Abelian/non-Abelian gauge theories
with critical couplings always reconnect classically in collision, by using
moduli space approximation. The moduli matrix formalism explicitly identifies a
well-defined set of the vortex moduli parameters. Our analysis of generic
geodesic motion in terms of those shows right-angle scattering in head-on
collision of two vortices, which is known to give the reconnection of the
strings.
