FINITE 3-PI CUT APPROXIMATION FOR THE PI-N(N)OVER-BAR FORM-FACTOR

Assuming the length of the 3pi cut to be finite and approximating the integrated 4pi amplitude by a constant, we derive an expression for th e piNNBAR form factor which is very close to that given by a simple po le. The specific predictions of the obtained form factor for the regio n of small momentum transfer are compared with existing effective pole formulas and discussed along the lines of the Goldberger-Treiman rela tion.