  We present results from numerical solution of the Einstein field equations
describing the head-on collision of two solitons boosted to ultra relativistic
energies. We show, for the first time, that at sufficiently high energies the
collision leads to black hole formation, consistent with hoop conjecture
arguments. This implies that the non-linear gravitational interaction between
the kinetic energy of the solitons causes gravitational collapse, and that
arguments for black hole formation in super-Planck scale particle collisions
are robust.
