Search for the radiative transitions $\psi (3770)\to \gamma {\eta }_c$ and $\gamma {\eta }_c(2S)$

Abstract

By using a 2.92 fb${}^{-1}$ data sample taken at $\sqrt{s}=3.773$ GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions $\psi (3770)\to \gamma {\eta }_c$ and $\gamma {\eta }_c(2S)$ through the hadronic decays ${\eta }_c({\eta }_c(2S))\to K_S^0{K}^{\pm }{\pi }^{\mp }$. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be $\mathcal{B}(\psi (3770)\to \gamma {\eta }_c)\times \mathcal{B}({\eta }_c\to K_S^0{K}^{\pm }{\pi }^{\mp })<1.6\times 10^{-5}$ and $\mathcal{B}(\psi (3770)\to \gamma {\eta }_c(2S))\times \mathcal{B}({\eta }_c(2S)\to K_S^0{K}^{\pm }{\pi }^{\mp })<5.6\times 10^{-6}$. Combining our result with world-average values of $\mathcal{B}({\eta }_c({\eta }_c(2S))\to K_S^0{K}^{\pm }{\pi }^{\mp })$, we find the branching fractions $\mathcal{B}(\psi (3770)\to \gamma {\eta }_c)<6.8\times 10^{-4}$ and $\mathcal{B}(\psi (3770)\to \gamma {\eta }_c(2S))<2.0\times 10^{-3}$ at a 90% confidence level.

arXiv comment10 pages, 4 figures

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• Coherent Exclusive Exponentiation For Precision Monte Carlo Calculations
• Measurements of e+e- -> K+K-eta, K+K-pi0 and KsK+pi- Cross Sections Using Initial State Radiation Events
• Spectroscopy at B-factories Using Hard Photon Emission
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• Charmless Final States and S--D-wave mixing in the ${\psi }^{\prime \prime }$
• Exotic and excited-state radiative transitions in charmonium from lattice QCD
• Measurements of the cross sections for $e^{+}{e}^{-}\to \mathrm{hadrons}$ at 3.650, 3.6648, 3.773 GeV and the branching fraction for $\psi (3770)\to \mathrm{non}-D\bar{D}$
• Measurements of the braching fractions for psi(3770)--> D0D0-bar,D+D-,DD-bar$ and the resonance parameters of psi(3770) and psi(2S)
• J/psi and psi(2S) Radiative Transitions to eta_c
• Observation of psi(3770)--> pi pi J/psi and Measurement of Gamma_{ee}[psi(2S)]
• Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-
• Decay of the psi(3770) to Light Hadrons
• Observation of psi(3770) --> gamma chi_c0
• First Observation of psi(3770) --> gamma chi_{c1} --> gamma gamma J/psi
• Measurement of B(J/psi->eta_c gamma) at KEDR
• Observation of ${\chi }_{c1}$ decays into vector meson pairs $\varphi \varphi$, $\omega \omega$, and $\omega \varphi$
• Study of B^{+-} -> K^{+-}(K_S K pi)^0 Decay and Determination of eta_c and eta_c(2S) Parameters
• Evidence for η_{c}(2S) in ψ(3686) \to γK_{S}^{0}K^{\pm}π^{\mp}π^{+}π^{-}
• Update of the measurement of the cross section for e^+e^- -> psi(3770) -> hadrons

Cited by in corpus (1)

• Studies of Charmonium at BESIII