The Pion-Nucleon Sigma Term and the Goldberger-Treiman Discrepancy

الأصل · EN

The pion-nucleon sigma term is shown to be equal to the Goldberger-Treiman discrepancy at tree level. Its value estimated this way is very sensitive to the pion-nucleon coupling constant gpi NN. This relation, when combined with the pion-nucleon S-wave scattering lengths, yields a new determination of gpi NN at tree level. The results of a one-loop analysis are also summarized determining an allowed range for the induced pseudoscalar coupling constant gₚ.