The Trace Anomaly in Chiral Dynamics: $γγ\to π^0π^0$ Scattering
Abstract
Description
The trace anomaly term in the low energy chiral Lagrangian is established by deriving a low energy theorem for $γγ\rightarrow π^0π^0$ scattering. It contributes to $σ(γγ\rightarrow π^0π^0)$ in the same order as the previously computed pion loop contribution. The coherent sum of the two contributions explains the shape of the measured cross section, while the magnitude is determined by the anomalous dimension of the quark mass operator.
3 pages, LateX, 0 figures (NOTE: PAPER IS INCORRECT AND IS WITHDRAWN)
3 pages, LateX, 0 figures (NOTE: PAPER IS INCORRECT AND IS WITHDRAWN)