Measurement of the Energy Dependence of the Form Factor inKL0→π+e+νDecay

Abstract

The pion energy distribution in ${K_L}^0\to \pi +e+\nu$ decay has been measured at the Princeton-Pennsylvania Accelerator using a wide-gap spark-chamber spectrometer. The results are consistent with vector interaction and an energy-independent form factor. The energy-dependence parameter $\lambda$ is found to be +0.020±0.013.