Pseudoscalar-Pseudovector Equivalence of Threshold Production and Absorption of Pions

Abstract

If one compares pseudoscalar-coupled and pseudovector-coupled theories of the $\pi \mathrm{NN}$ interaction, which incorporate the restrictions of partial conservation of axial-vector current and realistic nuclear dynamics, then the amplitudes for exclusive ($p$,${\pi }^{+}$) or (${\pi }^{-}$,$n$) become identical, to $O\left(G^3\right)$.