Search for ${\pi }^0$ decays to invisible particles

NA62 Collaboration

The NA62 experiment at the CERN SPS reports a study of a sample of $4\times 10^9$ tagged ${\pi }^0$ mesons from $K^{+}\to {\pi }^{+}{\pi }^0(\gamma )$, searching for the decay of the ${\pi }^0$ to invisibl…