Low-energy axial-vector form factors for K/sub e4/ decay based on broken chiral symmetry

We present an analysis of Kₑ₄ decay, particularly the process, K⁺→π⁺π⁻e⁺ν, using the techniques of current algebra and the $(3^{*},3)⨁(3,3^{*})$-breaking model. The axial-vector form factors with explicit dependence on the chiral-symmetry parameters are obtained at the points k²=p²=q²=0 and $k^2=m_K^{{}^2}$, p²=q²=0 and predictions compared with experimental rates and distributions. Discussion and comparison of our results with other recent analyses are also given. In particular, we find that $f_K=f_{\pi }$ and $f_{\kappa }=0$ gives good over-all agreement with the experimental rate, the fitted form factors, and the experimental distributions although small breakings in $\frac{f_K}{f_{\pi }}$ and somewhat larger breakings in $\frac{f_{\kappa }}{f_{\pi }}$ are not ruled out.