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

Using 14.0 million $\psi(2S) events collected with the BES-II detector, asearch for the decay of the $\jpsi$ to an invisible final state in $\psipto$ isperformed. The $\jpsi$ peak in the distribution of mass recoiling against the$\pi^+\pi^-$ is used to tag $\psi$ invisible decay. No signal is found, and anupper limit at the 90% confidence level is determined to be $1.2\times 10^{-2}$for the ratio $\frac{{\cal B}(\jpsi\ar {invisible})}{{\calB}(\jpsi\ar\mu^+\mu^-)}$. This is the first search for $J/\psi$ decay to aninvisible final state.

Search for the Invisible Decay of $\jpsi$ in $\psi(2S)\to\pi+\pi^-J/\psi$