Study of the D0 --> pi+ pi- pi0 decay at BABAR

The Dalitz-plot of the Decay D0 --> pi+ pi- pi0 measured by the BABAR Collaboration shows the structure of a final state having quantum numbers IG JPC = 0- 0--. An isospin analysis of the Daliz-plot finds that the I = 0 contribution is about 96%. This high I = 0 contribution is unexpected because the weak interaction violates the isospin.
Comment: 8 pages, 2 figures, talk given at the 13.th International Conference on Hadron Spectroscopy, Tallahassee, FL, USA, November 29 - December 4, 2009. The second version corrects the errors of the amplitudes in the second column of Table 1.