Strange baryons in the solitonic sector of the Nambu-Jona-Lasinio model

In a semibosonized Nambu-Jona-Lasinio model with an SU(3)RxSU(3)L chiral symmetry an explicit symmetry breaking term proportional to the strange quark mass is introduced. The mass splittings within the spin 1/2+ and spin 3/2+ baryon multiplets are studied. The SU(3) static Ansatz, chosen as the isospin embedding of the SU(2) hedgehog configuration, is adiabatically rotated in the flavor space. The fermion determinant is expanded up to the second order in angular velocity and up to the first order in the strange current quark mass. In this way strange and non-strange moments of inertia, analogous to the ones of the Skyrme model, and in addition new anomalous moments of inertia are obtained and numerically evaluated using selfconsistent solitonic solutions. The resulting collective hamiltonian is first treated in a strict perturbative way and second using the Yabu-Ando procedure. Based on experimental numbers for fπ, mπ and mK the mass splittings of the strange baryons are predicted within a few MeV. In the perturbative approach mass formulae of Gell-Mann, Okubo and Guadagnini are reproduced. The strangeness content of the proton comes out to be 20%. (orig.)