Measurement of the $CP$-even fraction of $D^0\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$

BESIII Collaboration, M. Ablikim, M. N. Achasov +563

A measurement of the $CP$-even fraction of the decay $D^0\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ is performed with a quantum-correlated $\psi (3770)\to D\bar{D}$ data sample collected by the BESI…