Kl3Form Factors in Current Algebra with Hard Pion and Kaon

Abstract

The $K_{l3\mathrm{}}$ form factors $f_{\pm }\left(q^2\right)$ are calculated using the current commutators, partially conserved axial-vector current, the Weinberg-type sum rules, and the Schnitzer-Weinberg technique with hard pions and kaons, which involves the domination of certain vertex functions by vector and axial-vector mesons. The results are very similar to those obtained recently by B. W. Lee using chiral dynamics and field-crurent identity.