WeChat Mini Program
Old Version Features

Measurement of the Η Transition Form Factor Through Η' →Π^+π^-Η Decay

BESIII Collaboration, M. Ablikim J. H. Zou, J. Zu

arXiv · Experiment(2025)

Cited 0|Views0
Abstract
Based on a sample of (1.0087±0.0044)×10^10 J/ψ events collected at BESIII, the transition form factor of the η meson is extracted by analyzing J/ψ→γη', η'→π^+π^-η, η→γ l^+l^- (l=e, μ) events. The measured slope of the transition form factor is Λ^-2=1.645±0.093_ stat.±0.024_ sys. (GeV/c^2)^-2 for the di-electron channel and Λ^-2=1.645±0.343_ stat.±0.017_ sys. (GeV/c^2)^-2 for the di-muon channel. The branching fractions for η→γ e^+e^- and η→γμ^+μ^- are measured to be ℬ(η→γ e^+e^-)=(6.79±0.04_ stat.±0.36_ sys.)× 10^-3 and ℬ(η→γμ^+μ^-)=(2.97±0.11_ stat.±0.07_ sys.)× 10^-4. By combining with the results based on the J/ψ→γη, η→γ e^+e^- events from the previous BESIII measurement, we determine Λ^-2=1.707±0.076_ stat.±0.029_ sys. (GeV/c^2)^-2 and ℬ(η→γ e^+e^-)=(6.93±0.28_ tot.)× 10^-3. In addition, we search for the dark photon (A') using the combined events. No significant signal is observed, and the upper limits on ℬ(η→γ A', A'→ e^+e^-) are set at 90% confidence level for different A' mass hypotheses.
More
Translated text
PDF
Bibtex
AI Read Science
Must-Reading Tree
Example
Generate MRT to find the research sequence of this paper
Data Disclaimer
The page data are from open Internet sources, cooperative publishers and automatic analysis results through AI technology. We do not make any commitments and guarantees for the validity, accuracy, correctness, reliability, completeness and timeliness of the page data. If you have any questions, please contact us by email: report@aminer.cn
Chat Paper
Summary is being generated by the instructions you defined