Anomalous decays of &eegr;' and &eegr; into four pions.

We calculate the branching ratios of the yet unmeasured &eegr;' decays into four pions, based on a combination of chiral perturbation theory and vector-meson dominance. The decays &eegr;' → 2(&pgr;+ &pgr;-) and &eegr;' → &pgr;+ &pgr;+&pgr;- are P-wave dominated and can largely be thought to proceed via two &rgr; resonances; we predict branching fractions of (1.0 ± 0.3) × 10-4 and (2.4 ± 0.7) × 10-4, respectively, not much lower than the current experimental upper limits. The decays &eegr;' → 4&pgr;0 and &eegr; → 4&pgr;0, in contrast, are D-wave driven as long as conservation of CP symmetry is assumed, and are significantly further suppressed; any experimental evidence for the decay &eegr; → 4&pgr;0 could almost certainly be interpreted as a signal of CP violation. We also calculate the CP-violating amplitudes for &eegr;' → 4&pgr;0 and &eegr; → 4&pgr;0 induced by the QCD &thetas;-term. [ABSTRACT FROM AUTHOR]