Strange baryons as chiral solitons of the Nambu-Jona-Lasinio model

Abstract

The Nambu-Jona-Lasinio model is investigated for three flavors. All parameters are determined in the mesonic sector by solving the gap and Bethe-Salpeter equations in the proper-time regularization scheme. The self-consistent SU(2) chiral soliton is embedded in the SU(3) flavor group and collectively quantized. The fermion determinant is expanded in terms of the collective angular velocity as well as in the quark mass difference. The resulting hamiltonian is diagonalized exactly providing the mass spectrum for the low-lying 1 2 + and 3 2 + baryons. The predicted mass splittings for baryons with different hypercharge are smaller than the experimental data. It is shown that this result is directly related to the too low prediction for the kaon decay constant. Excellent agreement with the experimental mass splittings is obtained when the physical value for the kaon decay constant is substituted.