Contribution of "Leakage" Matrix Elements to the Form Factors inKl3Decay

Abstract

A theoretical expression for the form factor $f_{-}\mathrm{}\left(t\right)\mathrm{}$ in $K_{l3\mathrm{}}$ decay is obtained from a sum rule based on the hadron weak-current commutation relations. The "leakage" matrix elements are found to make an important contribution to $f_{-}\mathrm{}\left(t\right)\mathrm{}$.