Nucleon-nucleon scattering in a chiral constituent quark model

We study the nucleon-nucleon interaction in a chiral constituent quark model by using the resonating group method, convenient for treating the interaction between composite particles. The calculated phase shifts for the S-3(1) and S-1(0) channels show the presence of a strong repulsive core due to the combined effect of the quark interchange and the spin-flavor structure of the effective quark-quark interaction. Such a symmetry structure stems from the pseudoscalar meson exchange between the quarks and is a consequence of the spontaneous breaking of the chiral symmetry. We perform single and coupled channel calculations and show the role of coupling of the Delta Delta and hidden color CC channels on the behavior of the phase shifts.