BESIII has recently collected a large data sample at the (3770) energy point, with an integrated luminosity of 20 fb^-1. The neutral D^0D^0 pairs produced at (3770) are in a C-odd correlated state, offering a unique laboratory for measuring the strong-phase differences between D^0 and D^0 decays. These parameters are crucial inputs for C\!P-violation studies in heavy-flavor physics, such as determining the CKM angle and charm-mixing parameters, searching for indirect C\!P violtion in the charm sector. In this presentation, we report recent progresses on new or improved measurements of the strong-phase differences in various neutral D decays at BESIII. We also present results on the C\!P-even fractions for multi-body decays. Finally, we discuss measurements of strong phase difference from additional D^0D^0 pairs produced at 4180 MeV.
Wenhan Shen (2026) studied this question.