  The NONLOCAL Bonn-B potential predicts 8.0 MeV binding energy for the triton
(in a charge-dependent 34-channel Faddeev calculation) which is about 0.4 MeV
more than the predictions by LOCAL NN potentials. We pin down origin and size
of the nonlocality in the Bonn potential, in analytic and numeric form. The
nonlocality is due to the use of the correct off-shell Feynman amplitude of
one-boson-exchange avoiding the commonly used on-shell approximations which
yield the local potentials. We also illustrate how this off-shell behavior
leads to more binding energy. We emphasize that the increased binding energy is
not due to on-shell differences (differences in the fit of the NN data or phase
shifts). In particular, the Bonn-B potential reproduces accurately the
$\epsilon_1$ mixing parameter up to 350 MeV as determined in the recent
Nijmegen multi-energy NN phase-shift analysis. Adding the relativistic effect
from the relativistic nucleon propagators in the Faddeev equations, brings the
Bonn-B result up to 8.2 MeV triton binding. This leaves a difference of only
0.3 MeV to experiment, which may possibly be explained by refinements in the
treatment of relativity and the inclusion of other nonlocalities (e.~g.,
quark-gluon exchange at short range). Thus, it is conceivable that a realistic
NN potential which describes the NN data up to 300 MeV correctly may explain
the triton binding energy without recourse to 3-N forces; relativity would play
a major role for this result.
