https://doi.org/10.1140/epjc/s2003-01378-x
theoretical physics
Anomalous 
decays: the triangle and box anomalies
1
LPNHE Paris VI/VII, 75252 , Paris, France
2
Fermilab, PO Box 500 MS 109, 60510, Batavia, IL, USA
We examine the decay modes 
within the context of the hidden local symmetry (HLS) model. Using numerical information derived in previous fits to the 
and Ve
+
e
- decay modes in isolation and the 
lineshape determined in a previous fit to the pion form factor, we show that all aspects of these decays can be predicted with fair accuracy. Freeing some parameters does not improve the picture. This is interpreted as strong evidence in favor of the box anomaly in the 
decays, which occurs at precisely the level expected. We also construct the set of equations defining the amplitudes for and 
at the chiral limit, as predicted from the anomalous HLS Lagrangian appropriately broken. This provides a set of four equations depending on only one parameter, instead of three for the traditional set. This is also shown to match the (two-angle, two-decay-constant) 
-
mixing scheme recently proposed and is also fairly well fulfilled by the data. The information returned from the fits also matches expectations from previously published fits to the decay modes in isolation.
© Springer-Verlag, 2003
