ON THE SOFT PION AND KAON THEOREMS IN NUCLEON AND NUCLEAR-INTERACTIONS

We investigate how pions and kaons behave when they interact with nucl eons and nuclei using the Goldberger-Treiman relation, and the Adler-W eisberger and Goldberger-Miyazawa-Oheme sum rules. In the pi-nucleon s ystem, a pion behaves as if it is almost massless whereas, in the pi-n ucleon system, the soft-pion approximation introduces errors of up to 20 approximately 30%. It is shown that a kaon, despite its relatively large mass, introduces errors of about 10 approximately 20% when it is assumed to interact with nucleons as a massless particle. Although a generalization to nuclear cases with crude approximations indicates qu alitatively similar results, any meaningful conclusion must wait for f uture measurement of K-nucleus scattering lengths and cross-sections.