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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

An experimental study of the $\eta'\to \pi^0\pi^0\eta \to 6\gamma$ decay hasbeen conducted with the best up-to-date statistical accuracy, by measuring$\eta'$ mesons produced in the $\gamma p \to \eta' p$ reaction with the A2tagged-photon facility at the Mainz Microtron, MAMI. The results obtained forthe standard parametrization of the $\eta'\to \pi^0\pi^0\eta$ matrix elementare consistent with the most recent results for $\eta'\to\pi\pi\eta$ decays,but have smaller uncertainties. The available statistics and experimentalresolution allowed, for the first time, an observation of a structure below the$\pi^+\pi^-$ mass threshold, the magnitude and sign of which, checked withinthe framework of the nonrelativistic effective-field theory, demonstrated goodagreement with the cusp that was predicted based on the $\pi\pi$ scatteringlength combination, $a_0-a_2$, extracted from $K \to 3\pi$ decays.

Measurement of the decay $\eta^{\prime}\to\pi^{0}\pi^{0}\eta$ at MAMI