Unexpected large relative strong phase and search for isospin breaking and $CP$ asymmetries in $J/ψ\to K^*(892)\bar K

BESIII Collaboration, M. Ablikim, M. N. Achasov +766

Using a direct scan of 26 energy points near the $J/\psi$ resonance, we perform the first measurement of the relative phase ${\varphi }_{\gamma ,3g}$ between the strong and electromagnetic amplitud…