Electromagnetic Pion Form Factor and Neutral Pion Decay Width

Abstract

The electromagnetic pion form factor, $F_{\ddot{I}}€(q^2)$, is calculated for spacelike-$q^2$ in impulse approximation using a confining quark propagator, $S$, and a dressed quark-photon vertex, $\hat{I}{“}_{\hat{I}}¼$, obtained from realistic, nonperturbative Dyson-Schwinger equation studies. Good agreement with the available data is obtained for $F_{\ddot{I}}€(q^2)$ and other pion observables, including the decay $\ddot{I}{€}^0\to {\hat{I}}^3{\hat{I}}^3$. This calculation suggests that soft, nonperturbative contributions dominate $F_{\ddot{I}}€(q^2)$ at presently accessible~$q^2$.

25 pages, LaTeX, elsart.sty, 5 figures, To appear in Nucl. Phys. A