  In this paper, we investigate the short-range repulsion given by the quark
cluster model employing an inverse scattering problem. We find that the local
potential which reproduces the same phase shifts to those given by the quark
cluster model has a strong repulsion at short distances in the NN1s0 channel.
There, however, appears an attractive pocket at very short distances due to a
rather weak repulsive behavior at very high energy region. This
repulsion-attractive-pocket structure becomes more manifest in the channel
which has an almost forbidden state, SigmaN(T=3/2)3s1. In order to see what
kinds of effects are important to reproduce the short-range repulsion in the
quark cluster model, we investigate the contribution coming from the
one-gluon-exchange potential and the normalization separately. It is clarified
that the gluon exchange constructs the short-range repulsion in the NN1s0 while
the quark Pauli-blocking effect governs the feature of the repulsive behavior
in the SigmaN(T=3/2)3s1 channel.
