CONNECTION BETWEEN FPI(T) AND AMPLITUDES FOR PIPI-]PIPI AND PIPI-]PIA1

The current-algebra connection between the pion electromagnetic form factor Fπ(t) and the amplitudes for ππ→ππ and ππ→πA1 is examined by explicitly extrapolating off the pion mass shell the matrix element π|Aμ|ππ which is taken to be dominated by π and A1 poles and possible subtractions. It is found that the connection is broken by the presence of an almost arbitrary subtraction function. In particular the Aρπ interaction remains arbitrary as well as the form for Fπ(t). The results are applied briefly to the Veneziano model. © 1969 The American Physical Society.