English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We amend a recent dispersive analysis of the anomalous $\eta$ decay process$\eta\to\pi^+\pi^-\gamma$ by the effects of the $a_2$ tensor meson, thelowest-lying resonance that can contribute in the $\pi\eta$ system. While thenet effects on the measured decay spectrum are small, they may be morepronounced for the analogous $\eta'$ decay. There are nonnegligibleconsequences for the $\eta$ transition form factor, which is an importantquantity for the hadronic light-by-light scattering contribution to the muon'sanomalous magnetic moment. We predict total and differential cross sections, aswell as a marked forward-backward asymmetry, for the crossed process$\gamma\pi^-\to\pi^-\eta$ that could be measured in Primakoff reactions in thefuture.

Anomalous decay and scattering processes of the eta meson