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تسجيل مستخدم جديدMeasurements of the mass and width of the eta_c using psi -> gamma eta_c
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The mass and width of the lowest lying S-wave spin singlet charmonium state, the eta_c, are measured using a data sample of 1.06x10^8 psi decays collected with the BESIII detector at the BEPCII storage ring. We use a model that incorporates interference between the signal reaction, psi -> gamma eta_c, and a non-resonant radiative background to successfully describe the line shape of the eta_c. We measure the eta_c mass to be 2984.3 +- 0.6 +- 0.6 MeV/c^2 and the total width to be 32.0 +- 1.2 +- 1.0 MeV, where the first errors are statistical and the second are systematic.
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We present a study of the inclusive photon spectra from 5.9 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of radiative decay J/psi to eta_c gamma, eta_c width and mass. Our preli
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We present a study of the inclusive photon spectrum from 6.3 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/psi -> eta_c gamma, eta_c width and mass. Taki
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We report on the observation of the eta_c^ (2 ^1S_0), the radial excitation of eta_c (1 ^1S_0) ground state of charmonium, in the two-photon fusion reaction gamma gamma to eta_c^ to K_S^0 K^{pm} pi^{mp} in 13.4 fb^{-1} of CLEO II/II.V data and 9.2 fb
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With the help of the largest data samples of $J/psi$ and $psi(2S)$ events ever produced in $e^+e^-$ annihilations, the three singlet charmonium states, $eta_c(1S)$, $eta_c(2S)$ and $h_c(1P)$, have been extensively studied at the BESIII experiment. In
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The process $psi(3686) to pi^0 h_c, h_c to gamma eta_c$ has been studied with a data sample of $106 pm 4$ million $psi(3686)$ events collected with the BESIII detector at the BEPCII storage ring. The mass and width of the $P$-wave charmonium spin-sin
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