Upper Limit on the Branching Ratio for the Decay ${\pi }^0\to \nu \bar{\nu }$

E949 Collaboration, A. V. Artamonov

A sample of kinematically identified $K^{+}\to {\pi }^{+}{\pi }^0$ decays obtained with the E949 detector was used to search for the helicity-suppressed decay ${\pi }^0\to \nu \bar{\nu }$ resulting in an…