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

Based on a sample of $1.31\times10^9$ $J/\psi$ events collected with theBESIII detector, the matrix elements for the decays$\eta^{\prime}\to\eta\pi^{+}\pi^{-}$ and $\eta^{\prime}\to\eta \pi^{0}\pi^{0}$are determined using 351,016 $\eta^{\prime}\to(\eta\to\gamma\gamma)\pi^+\pi^-$and 56,249 $\eta^{\prime}\to(\eta\to\gamma\gamma)\pi^0\pi^0$ events withbackground levels less than 1\%. Two commonly used representations are used todescribe the Dalitz plot density. We find that an assumption of a linearamplitude does not describe the data well. A small deviation of the obtainedmatrix elements between $\eta^{\prime}\to\eta\pi^{+}\pi^{-}$ and$\eta^{\prime}\to\eta \pi^{0}\pi^{0}$ is probably caused by the mass differencebetween charged and neutral pions or radiative corrections. No cusp structurein $\eta^{\prime}\to\eta \pi^{0}\pi^{0}$ is observed.

Measurement of the matrix elements for the decays $\eta^{\prime}\rightarrow\eta\pi^+\pi^-$ and $\eta^{\prime}\rightarrow\eta\pi^0\pi^0$