A quantum-mechanical technique is used within the framework of U(2)
super-Yang-Mills theory to investigate what happens in the process after
recombination of two D-p-branes at one angle. Two types of initial conditions
are considered, one of which with p=4 is a candidate of inflation mechanism.
It is observed that the branes' shapes come to have three extremes due to
localization of tachyon condensation. Furthermore, open string pairs connecting
the decaying D-branes are shown to be created; most part of the released energy
is used to create them. It also strongly suggests that creation of closed
strings happens afterward. Closed strings as gravitational radiation from the
D-branes are also shown to be created. A few speculations are also given on
implications of the above phenomena for an inflation model.Comment: 39pages,Latex,9 eps-figs,in v4 creation of closed strings discussed,
energy dissipation by rads. replaced by that by creations of strings; in v5
logic to argue pair-creation of open strings corrected, their number density,
energy distribution to them, energy flux of gravi. radiation evaluated
quantitatively, 2 intuitive figs.added, 1 initial cond. modified: overlapping
-> parallel, refs. on rolling tachyons added;in v6 distribution of the
releassed energy corrected:its most part used to created open string pair