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 KTeV E799 experiment has conducted a search for the rare d ecayKL → π0π0μ+μ−, which includes a search for the light neutral boson X0 that decays toμ+μ−. A possible new light neutral bosonX0 was reported by the HyperCP experiment with a mass of 214.3 Me V/c2. In this paper we report no evidence of KL → π0π0X0 → π0π0μ+μ− and set an upper limit on the branching ratio for KL → π0π0X0 → π0π0μ+μ− of 9.44×10−11 at the 90% confidence level. In addition, an upper limit on the branching ratio for KL → π0π0μ+μ− of 8.63×10−11 at the 90% confidence level is also presented.

Search for a New Neutral Boson in the Rare Decay $K_L\rightarrow \pi^0 \pi^0 \mu^+ \mu^-$ from KTeV