The values of the coupling constants ${f_{\pi {}_{}{}^6{}_{}{}^{}\mathrm{Li}{}_{}{}^6{}_{}{}^{}\mathrm{Be}}}^2=0.07\mathrm{}$, ${f_{\pi {}_{}{}^{12}{}_{}{}^{}\mathrm{C}{}_{}{}^{12}{}_{}{}^{}\mathrm{N}}}^2=0.004\mathrm{}$, and ${f_{\pi {}_{}{}^{14}{}_{}{}^{}\mathrm{N}{}_{}{}^{14}{}_{}{}^{}\mathrm{O}}}^2=0.00014\mathrm{}$ have been extracted from the pological treatment of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}(p, n){}_{}{}^6{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(p, n){}_{}{}^{12}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}(p, n){}_{}{}^{14}{}_{}{}^{}\mathrm{O}$ reactions. A critical discussion of our present knowledge of the pion couplings to these nuclei and of existing methods of their determination is given.

NUCLEAR REACTIONS Initial nucleus-pion-final nucleus coupling constants. PCAC hypothesis. Analyticity. ${}_{}{}^6{}_{}{}^{}\mathrm{Li}(p, n){}_{}{}^6{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(p, n){}_{}{}^{12}{}_{}{}^{}\mathrm{N}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}(p, n){}_{}{}^{14}{}_{}{}^{}\mathrm{O}$ at 0.144 GeV.

• Received 26 February 1980

DOI:https://doi.org/10.1103/PhysRevC.22.2151