The Pion Form Factor. Where Does It Come From?

Abstract

We discuss the nonleading, ``soft" contribution to the pion form factor at intermediate momentum transfer within operator product expansion approach. We argue, that the corresponding contribution can temporarily {\bf simulate} the leading twist behavior in the extent region of $Q^2:3Ge{V}^2\le Q^2\le 35Ge{V}^2$, where $Q^{2}F(Q^2)\sim const.$ Such a mechanism, if it is correct, would be an explanation of the phenomenological success of the dimensional counting rules (which theoretically correspond to the keeping of the asymptotically leading terms only) at available, very modest $Q^2$. The relation with quark model calculation is also discussed.

Comments: LATEX, 10 pgs. The basic, starting point of the entire approach is clarified. All numerical results are the same