  We formulate a Lippmann-Schwinger-type resonating-group equation to calculate
invariant amplitudes of the quark-model baryon-baryon interaction. When applied
to our recent SU6 quark model for the nucleon-nucleon and hyperon-nucleon
interactions, this technique yields very accurate phase-shift parameters for
all partial waves up to the energies of several GeV. The technique also has a
merit of a straightforward extension to the G-matrix equation. A new analytic
method is proposed to calculate the quark-exchange Born kernel for the
momentum-dependent two-body interaction. The partial-wave decomposition in the
momentum representation is carried out numerically. The invariant amplitudes
are then used to calculate single-nucleon potentials in normal nuclear matter
for high incident momenta q_1 > 3 (1/fm), in which the so-called t^eff-rho
prescription is found to be a good approximation to the single-particle
potentials directly calculated in the lowest-order Brueckner theory.
