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Relativistic chiral SU(3) symmetry, large N_c sum rules and meson-baryon scattering

M. F. M. Lutz·E. E. Kolomeitsev
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Abstract

The relativistic chiral SU(3) Lagrangian is used to describe kaon-nucleon scattering imposing constraints from the pion-nucleon sector and the axial-vector coupling constants of the baryon octet states. We solve the covariant coupled-channel Bethe-Salpeter equation with the interaction kernel truncated at chiral order Q^3 where we include only those terms which are leading in the large N_c limit of QCD. The baryon decuplet states are an important explicit ingredient in our scheme, because together with the baryon octet states they form the large N_c baryon ground states of QCD. Part of our technical developments is a minimal chiral subtraction scheme within dimensional regularization, which leads to a manifest realization of the covariant chiral counting rules. All SU(3) symmetry-breaking effects are well controlled by the combined chiral and large N_c expansion, but still found to play a crucial role in understanding the empirical data. We achieve an excellent description of the data set typically up to laboratory momenta of p_lab about 500 MeV.

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M. F. M. Lutz, E. E. Kolomeitsev. 2001-05-18. Relativistic chiral SU(3) symmetry, large N_c sum rules and meson-baryon scattering. https://doi.org/10.1016/s0375-9474(01)01312-4

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