Scalar and Tensor Force Contribution to the Nucleon-Nucleon Interaction Within a Chiral Constituent Quark Model

The nucleon-nucleon problem is studied as a six-quark system in a nonrelativistic chiral constituent quark model where the Hamiltonian contains a linear confinement and a pseudoscalar meson (Goldstone boson) exchange interaction between the quarks [1, 2]. This hyperfine interaction has a long-range Yukawa-type part, depending on the mass of the exchanged meson and a short-range part, mainly responsible for the good description of the baryon spectra. The nucleon-nucleon phases shifts are calculated using the resonating group method, convenient for treating the interaction between composite particles. The behavior of the phase shifts for the S1 and S0 channels show the presence of a strong repulsive core. We show that the introduction of a scalar σ -meson exchange [3] and the tensor force [4] associated to the pseudoscalar meson exchange interaction lead to a satisfactory agreement with the experiencal phase shifts.