  We develop an analytical theory of reconnection between colliding, twisted
magnetic flux tubes. Our analysis is restricted to direct collisions between
parallel tubes and is based on the collision dynamics worked out by Bogdan
(1984). We show that there is a range of collision velocities for which neutral
point reconnection of the Parker-Sweet type can occur, and a smaller range for
which reconnection leads to coalescence. Mean velocities within the solar
convection zone are probably significantly greater than the upper limit for
coalescence. This suggests that the majority of flux tube collisions do not
result in merging, unless the frictional coupling of the tubes to the
background flow is extremely strong.
