We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e＋e collider. We measure the branching fraction of radiative decay J/ψ→ηcγ, ηc widt...We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e＋e collider. We measure the branching fraction of radiative decay J/ψ→ηcγ, ηc width and mass. Our preliminary results are： M（ηc） = 2979.4± 1.5 ± 1.9 MeV/c^2, Г（ηc） = 27.8±5.1 ±3.3 MeV, B（Jψ→ηcγ） = （2.34±0.15±0.40）%.展开更多
We report results of experiments performed with the KEDR detector at the VEPP-4M e^＋e^- collider. They include precise measurement of the D^0 and D^± meson masses, determination of the ψ（3770） resonance param...We report results of experiments performed with the KEDR detector at the VEPP-4M e^＋e^- collider. They include precise measurement of the D^0 and D^± meson masses, determination of the ψ（3770） resonance parameters, and a search for narrow resonances in e^＋e^- annihilation at center-of-mass energies between 1.85 and 3.1 GeV.展开更多
The beam energy measurement system at BEPCII is composed of there parts： laser source and optics system, laser-electron interaction system and High Purity Germanium （HPGe） detector system. The special components an...The beam energy measurement system at BEPCII is composed of there parts： laser source and optics system, laser-electron interaction system and High Purity Germanium （HPGe） detector system. The special components and construction of each part are introduced, especially about radiation background measurement in the storage ring, which is of great importance for the safe commissioning of HPGe detector.展开更多
基金Supported by the Russian Foundation for Basic Research,grants 08-02-00258,08-02-00258RF Presidential Grant for Sc. Sch. NSh-5655.2008.2
文摘We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e＋e collider. We measure the branching fraction of radiative decay J/ψ→ηcγ, ηc width and mass. Our preliminary results are： M（ηc） = 2979.4± 1.5 ± 1.9 MeV/c^2, Г（ηc） = 27.8±5.1 ±3.3 MeV, B（Jψ→ηcγ） = （2.34±0.15±0.40）%.
基金Supported by Russian Foundation for Basic Research,Grant 04-02-16712,07-02-00816,07-02-01162RF Presidential Grant for Sc.Sch.NSh-5655.2008.2
文摘We report results of experiments performed with the KEDR detector at the VEPP-4M e^＋e^- collider. They include precise measurement of the D^0 and D^± meson masses, determination of the ψ（3770） resonance parameters, and a search for narrow resonances in e^＋e^- annihilation at center-of-mass energies between 1.85 and 3.1 GeV.
基金Supported by National Natural Science Foundation of China (10775412,10825524)Instrument Developing Project of the Chinese Academy of Sciences (YZ200713)+4 种基金Major State Basic Research Development Program (2009CB825203,2009CB825206)Knowledge Innovation Project of The Chinese Academy of Sciences (KJCX2-YW-N29)RFBR 08-02-00328-a,08-02-00251-a,08-02-92200-NSFC-aSB RAS joint project No.32 for fundamental researcher with CASthe Department of Energy under Contract No.DE-FG02-04ER41291 (U.Hawaii)
文摘The beam energy measurement system at BEPCII is composed of there parts： laser source and optics system, laser-electron interaction system and High Purity Germanium （HPGe） detector system. The special components and construction of each part are introduced, especially about radiation background measurement in the storage ring, which is of great importance for the safe commissioning of HPGe detector.
