On the Color-Singlet States in Many-Quark Model with the su(4)-Algebraic   Structure. II
  Ground-state energies are investigated in a many-quark model with pairing interactions, which has the su(4)-algebraic structure. Exact eigenstates in the boson realization method are constructed by imposing a color-singlet condition developed in the previous paper. An interaction term breaking the su(4)-dynamical symmetry plays an important role to determine the ground state. As a result, a quark-pairing state or a quark-triplet state as a nucleon is realized with a certain value of a variable which is regarded as an order parameter. In addition to the parameter regions in which these ground states are realized, it is shown that there are two transition regions between the quark-pairing and the quark-triplet states with different values of the order parameter. 
Y.Tsue (Kochi Univ., Japan), C.Providencia (Univ. de Coimbra,   Portugal), J.da Providencia (Univ. de Coimbra, Portugal), M....
nucl-th