  We calculate the leading order interactions of massless D-brane excitations.
Their 4-point functions are found to be identical to those found in type I
theory. The amplitude for two massless D-brane fluctuations to produce a
massless closed string is found to possess interesting new structure. As a
function of its single kinematic invariant, it displays an infinite sequence of
alternating zeros and poles. At high transverse momenta, this amplitude decays
exponentially, indicating a growing effective thickness of the D-brane. This
amplitude is the leading process by which non-extremal D-branes produce Hawking
radiation.

High Energy Physics - Theory