Hund's rule coupling as the microscopic origin of the spin-triplet pairingin a correlated and degenerate band system

We propose that the spin-triplet pairing can originate from the intraatomic Hund's rule exchange in a degenerate d-band system. The role of this inter action in the pairing is decisive when accounted for in conjunction with ra ther strong correlations induced by the direct Coulomb interactions. The su perconducting-gap value is obtained in the saddle-point approximation for t he Coulomb correlations, treated in the auxiliary Bose field approach, whic h is combined with the mean-field approximation of the BCS type for the pai ring part.