2 papers
hep-ex2025
Precision Measurement of - Mass Difference
BESIII Collaboration, M. Ablikim, M. N. Achasov +684
We measure the mass difference between and , , using the decay chain , utilizing annihi…
hep-ex2025
First determination of the full spin density matrix in
BESIII Collaboration, M. Ablikim, M. N. Achasov +688
Using events collected with the BESIII detector, we present the first complete determination of the spin density matrix in .…