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

Cross sections of the process $e^+e^-\to\pi^0\pi^0 J/\psi$ at center-of-massenergies between 3.808 and 4.600 GeV are measured with high precision by using12.4 $fb^{-1}$ of data samples collected with the BESIII detector operating atthe BEPCII collider facility. A fit to the measured energy-dependent crosssections confirms the existence of the charmonium-like state $Y(4220)$. Themass and width of the $Y(4220)$ are determined to be $(4220.4\pm2.4\pm2.3)$${\rm MeV}/c^{2}$ and $(46.2\pm4.7\pm2.1)$ MeV, respectively, where the firstuncertainties are statistical and the second systematic. The mass and width areconsistent with those measured in the process $e^+e^-\to\pi^+\pi^- J/\psi$. Theneutral charmonium-like state $Z_c(3900)^0$ is observed prominently in the$\pi^0 J/\psi$ invariant-mass spectrum, and, for the first time, an amplitudeanalysis is performed to study its properties. The spin-parity of $Z_c(3900)^0$is determined to be $J^{P}=1^{+}$, and the pole position is$(3893.1\pm2.2\pm3.0)-i(22.2\pm2.6\pm7.0)$ ${\rm MeV}/c^2$, which is consistentwith previous studies of electrically charged $Z_c(3900)^\pm$. In addition,cross sections of $e^+e^-\to\pi^0 Z_c(3900)^0\to \pi^0\pi^0 J/\psi$ areextracted, and the corresponding lineshape is found to agree with that of the$Y(4220)$.

Study of the process $e^+e^-\to\pi^0\pi^0 J/\psi$ and neutral charmonium-like state $Z_c(3900)^0$