Study of the D0→π+π−π0 decay at BABAR

The Dalitz‐plot of the decay D0→π+π−π0 measured by the BABAR collaboration shows the structure of a final state having quantum numbers IGJPC = 0−0−−. An isospin analysis of this Dalitz‐plot finds that the fraction of the I = 0 contribution is about 96%. This high I = 0 contribution is unexpected because the weak interaction violates the isospin.