Abstract
We provide a model-independent determination of the quantity . Our approach rests only on chiral symmetry and data from the decay of the eta into three neutral pions. Since the low-energy prediction at next-to-leading order fails to reproduce the experimental results, we keep the strong interaction correction as an unknown parameter. As a first step, we relate this parameter to the quark mass difference using data from the Dalitz plot. A similar relation is obtained using data from the decay width. Combining both relations we obtain . The preceding value, combined with lattice determinations, leads to the values and .
- Received 26 March 2008
DOI:https://doi.org/10.1103/PhysRevD.78.034032
©2008 American Physical Society