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

The BESIII Collaboration recently reported the observation of the$a_0(980)^0-f_0(980)$ mixing in the isospin breaking decay $J/\psi\to\eta\pi^0\phi$. In the Dalitz plot for that decay with the $\eta$ reconstructedfrom two photons, there is a band around $1.4$~GeV on the $\pi^0 \phi$distribution. In general, this peak can be due to a resonance or a kinematiceffect. In this paper, we study the effects of a set of $K^*K\bar K$ trianglediagrams, and show that due to triangle singularities such diagrams can lead toa peak around 1.4~GeV in the $\pi^0\phi$ invariant mass distribution. TheDalitz plot induced by such a mechanism has a feature consistent with theBESIII observation, namely events along the band accumulate at both ends closeto the Dalitz plot boundary. The effect of the same mechanism on the $J/\psi\to\pi^0\pi^0\phi$ and $J/\psi \to \eta\pi^0 K^+K^-$ decays are also investigated.We suggest to take more data for the $J/\psi\to \eta\pi^0\phi\to \eta\pi^0 K^+K^-$ and check whether the structure around $1.4$~GeV persists for the $K^+K^-$invariant mass away from the $\phi$ mass region. This is crucial forunderstanding whether the band is due to triangle singularities or due to aresonance. Were it the latter, the band should remain while it would not if itis due to the former.

Triangle singularities in ${J/\psi\rightarrow\eta\pi^0\phi}$ and ${\pi^0\pi^0\phi}$