New measurement of the Dalitz-decay branching ratio of theπ0

Abstract

An experiment measuring the Dalitz-decay branching ratio of the ${\pi }^0$ meson has been performed at the Clinton P. Anderson Meson Physics Facility (LAMPF). The result is $\frac{\Gamma ({\pi }^0\to e^{+}{e}^{-}\gamma )}{\Gamma ({\pi }^0\to \gamma \gamma )}=(1.25\mathrm{}\pm 0.04\pm 0.01)\times {10}^{-2\mathrm{}}$, where the first error is due to statistics and the second is an estimate of systematic effects. This result is in agreement with the one previous high-statistics measurement and with theoretical expectations.