The Goldberger-Treiman discrepancy in SU(3)

Abstract

The Goldberger-Treiman discrepancy in SU(3) is analyzed in the framework of heavy baryon chiral perturbation theory (HBChPT). It is shown that the discrepancy at leading order is entirely given by counterterms from the order p<SUP>3</SUP> Lagrangian, and that the first subleading corrections are suppressed by two powers in the HBChPT expansion. These subleading corrections include meson-loop contributions as well as counterterms from the order p<SUP>5</SUP> Lagrangian. Some one-loop contributions are calculated and found to be small. Using the three discrepancies (πNN, KNλ and KNΣ) which can be extracted from existing experimental data, the authors find that the HBChPT calculation favors the smaller g(πNN) values obtained in recent partial wave analyses.