Light Mesons elm Form Factor and Running Coupling Effects

Abstract

The pion and kaon electromagnetic form factors $F_M(Q^2)$ are calculated at the leading order of pQCD using the running coupling constant method. In computations dependence of the meson distribution amplitudes on the hard scale $Q^2$ is taken into account. The Borel transform and resummed expression for $F_M(Q^2)$ are found. The effect of the next-to-leading order term in expansion of ${\alpha }_S(\lambda Q^2)$ in terms of ${\alpha }_S(Q^2)$ on the pion form factor $F_{\pi }(Q^2)$ is discussed, comparison is made with the infrared matching scheme's result.

Comments: 10 pages, 2 figures. Talk given at the Euroconference QCD98, Montpellier 2-8th July 1998, France; to appear in Proceedings