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C. F. Fritzsch

Publications and source records attributed to C. F. Fritzsch.

3 recordsLinked to original sources
arXiv2023

Observation of $J/ψ$ decays to $e^{+}e^{-}e^{+}e^{-}$ and $e^{+}e^{-}μ^{+}μ^{-}$

Using a data sample of $4.481\times 10^8 ψ^\prime$ events collected with the BESIII detector, we report the first observation of the four-lepton-decays $J/ψ\to e^+e^-e^+e^-$ and $J/ψ\to e^+e^-μ^+μ^-$ utilizing the process $ψ^\prime\to π^+π^- J/ψ$. The branching fractions are determined to be $[5.48\pm0.31~(\rm stat)\pm0.45~(\rm syst)]\times 10^{-5}$ and $[3.53~\pm0.22~(\rm stat)\pm0.13~(\rm syst)]\times 10^{-5}$, respectively. The results are consistent with theoretical predictions. No significant signal is observed for $J/ψ\to μ^+μ^-μ^+μ^-$, and an upper limit on the branching fraction is set at $1.6\times 10^{-6}$ at the 90$\%$ confidence level. A CP asymmetry observable is constructed for the first two channels, which is measured to be $(-0.012\pm0.054\pm0.010)$ and $(0.062\pm0.059\pm0.006)$, respectively. No evidence for CP violation is observed in this process.

hep-ex↗
arXiv2021

Observation of $J/ψ$ Electromagnetic Dalitz Decays to $X(1835)$, $X(2120)$ and $X(2370)$

Using a sample of about 10 billion $J/ψ$ events collected at a center-of-mass energy $\sqrt s = 3.097$ GeV with the BESIII detector, the electromagnetic Dalitz decays $J/ψ\to e^+e^- π^+ π^- η'$, with $η'\toγπ^+ π^-$ and $η'\toπ^+π^-η$, have been studied. The decay $J/ψ\to e^+ e^- X(1835)$ is observed with a significance of $15σ$, and the transition form factor of $J/ψ\to e^+e^-X(1835)$ is presented for the first time. The intermediate states $X(2120)$ and $X(2370)$ are also observed in the $π^+ π^- η'$ invariant mass spectrum with significances of $5.3σ$ and $7.3σ$. The corresponding product branching fractions for $J/ψ\to e^+e^-X$, $X\toπ^+π^-η'$ $(X=X(1835), X(2120)$ and $X(2370))$, are reported.

hep-ex↗
arXiv2021

Cross section measurements of the $e^+e^-\to D^{*+}D^{*-}$ and $e^+e^-\to D^{*+}D^{-}$ processes at center-of-mass energies from 4.085 to 4.600 GeV

The Born cross sections of the $e^+e^-\to D^{*+}D^{*-}$ and $e^+e^-\to D^{*+}D^{-}$ processes are measured using $e^+e^-$ collision data collected with the BESIII experiment at center-of-mass energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of $15.7~{\rm fb}^{-1}$. The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.

hep-ex↗