Hard-Pion Current-Algebra Calculation of meson Processes—Three-Point Functions

Abstract

Hard-pion techniques are presented for calculating vertex functions involving $\ensuremath{\pi}$, $\ensuremath{\rho}$, ${A}_{1}$, and $\ensuremath{\sigma}$ mesons. The development of the method involves the following assumptions: (a) saturation of intermediate sums by single mesons, (b) chiral $\mathrm{SU}(2)\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(2)$ algebra commutation relations, (c) conservation of vector current, and (d) partial conservation of axial-vector current.