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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Using the full data sample of 980 $\mathrm{fb}^{-1}$ collected with the Belledetector at the KEKB asymmetric energy electron-positron collider, we reportthe results of the first search for the rare semileptonic decays $\Xi_c^0 \to\Xi^0\ell^+\ell^-$ ($\ell=e$ or $\mu)$. No significant signals are observed inthe $\Xi^0\ell^+\ell^-$ invariant-mass distributions. Taking the decay $\Xi_c^0\to \Xi^- \pi^+$ as the normalization mode, we report 90\% credibility upperlimits on the branching fraction ratios ${\cal{B}} (\Xi_c^0 \to \Xi^0 e^+ e^-)/ {\cal{B}}(\Xi_c^0\to \Xi^-\pi^+) < 6.7 \times 10^{-3}$ and ${\cal{B}}(\Xi_c^0 \to \Xi^0 \mu^+ \mu^-) / {\cal{B}}(\Xi_c^0\to \Xi^-\pi^+) < 4.3 \times10^{-3}$ based on the phase-space assumption for signal decays. The 90\%credibility upper limits on the absolute branching fractions of ${\cal{B}}(\Xi_c^0 \to \Xi^0 e^+ e^-)$ and ${\cal{B}} (\Xi_c^0 \to \Xi^0 \mu^+ \mu^-)$are found to be $9.9 \times 10^{-5}$ and $6.5 \times 10^{-5}$, respectively.

Search for the semileptonic decays $\Xi_c^0 \to \Xi^0\ell^+\ell^-$ at Belle