eta -> pi^+ pi^- pi^0 gamma in Chiral Perturbation Theory

Abstract

We analyse the radiative decay $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0\gamma$ in the low--energy expansion of the Standard Model. We employ the notion of ``generalized bremsstrahlung'' to take full advantage of the theoretical and experimental information on the corresponding non-radiative $\eta \to 3\pi$ decay. The direct emission amplitude of $\mathcal{O}(p^4)$ is due to one-loop diagrams with intermediate pions (isospin violating) and kaons (isospin conserving). The isospin conserving contributions to direct emission, including vector meson exchange appearing at $\mathcal{O}(p^6)$, are suppressed.

13 pages, 1 fig; minor modifications (results unchanged)

References in corpus (4)

• Dispersive analysis of the decay eta -> 3 pi
• Final State Interactions and Khuri-Treiman Equations in $\eta \to 3\pi$ decays
• Radiative Four--Meson Amplitudes in Chiral Perturbation Theory
• Chiral Perturbation Theory Predictions for $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^0\gamma$

Cited by in corpus (3)

• Chiral perturbation theory
• Precision tests of fundamental physics with $\eta$ and ${\eta }^{\prime }$ mesons
• Structural Vertices of Extended SU(3)-Chiral Lagrangians in the Large-N_c Approach