Proton-neutron interactions in N≈Z nuclei -: art. no. 024301

Proton-neutron (p-n) interactions and their various aspects in N approximate to Z nuclei of g(9/2) and f(7/2) subshells are studied using a schematic model interaction with four force parameters proposed recently. It is shown that the model interaction reproduces well observed physical quantities: the double differences of binding energies, symmetry energy, Wigner energy, odd-even mass difference, and separation energy, which testifies to the reliability of the model interaction and its p-n interactions. First of all, the double differences of binding energies are used for probing the p-n interactions. The analysis reveals different contributions of the isoscalar and isovector p-n pairing interactions to two types of double differences of binding energies, and also indicates the importance of a unique form of isoscalar p-n pairing force with all J components. Next, it is shown that this p-n force is closely related to the symmetry energy and the Wigner energy. Other calculations demonstrate the significant roles of p-n interactions in the odd-even mass difference and in the separation energy at N approximate to Z. [S0556-2813(99)00808-0].