<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mi>l</mml:mi><mml:mn>3</mml:mn><mml:mn/></mml:mrow></mml:msub></mml:mrow></mml:math>Form Factors and the Scaling Behavior of Spin-0 Fields

Motivated by scaling considerations we formulate a theory of ${K}_{l3}$ decay based on the Kemmer equation. We find that our theory (1) has a symmetry-breaking parameter of order 10-30% which agrees with experiment, (2) makes a definite testable prediction of a kinematic zero at $t={({m}_{K}+{m}_{\ensuremath{\pi}})}^{2}$ in the "effective" scalar form factor, and (3) yields a modified Callan-Treiman relation which improves agreement with experiment.