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arXiv · 1002.2071

Measurement of J/psi to eta_c gamma at KEDR

V. V. Anashin·V. M. Aulchenko·E. M. Baldin·A. K. Barladyan·A. Yu. Barnyakov·M. Yu. Barnyakov·S. E. Baru·I. V. Bedny·O. L. Beloborodova·A. E. Blinov·V. E. Blinov·A. V. Bobrov·V. S. Bobrovnikov·A. V. Bogomyagkov·A. E. Bondar·A. R. Buzykaev·S. I. Eidelman·Yu. M. Glukhovchenko·V. V. Gulevich·D. V. Gusev·S. E. Karnaev·G. V. Karpov·S. V. Karpov·T. A. Kharlamova·V. A. Kiselev·S. A. Kononov·K. Yu. Kotov·E. A. Kravchenko·V. F. Kulikov·G. Ya. Kurkin·E. A. Kuper·E. B. Levichev·D. A. Maksimov·V. M. Malyshev·A. L. Maslennikov·A. S. Medvedko·O. I. Meshkov·A. I. Milstein·S. I. Mishnev·I. I. Morozov·N. Yu. Muchnoi·V. V. Neufeld·S. A. Nikitin·I. B. Nikolaev·I. N. Okunev·A. P. Onuchin·S. B. Oreshkin·I. O. Orlov·A. A. Osipov·S. V. Peleganchuk·S. G. Pivovarov·P. A. Piminov·V. V. Petrov·A. O. Poluektov·I. N. Popkov·G. E. Pospelov·V. G. Prisekin·A. A. Ruban·V. K. Sandyrev·G. A. Savinov·A. G. Shamov·D. N. Shatilov·B. A. Shwartz·E. A. Simonov·S. V. Sinyatkin·Yu. I. Skovpen·A. N. Skrinsky·V. V. Smaluk·A. M. Sukharev·E. V. Starostina·A. A. Talyshev·V. A. Tayursky·V. I. Telnov·Yu. A. Tikhonov·K. Yu. Todyshev·G. M. Tumaikin·Yu. V. Usov·A. I. Vorobiov·A. N. Yushkov·V. N. Zhilich·V. V. Zhulanov·A. N. Zhuravlev
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Abstract

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 preliminary results are: M(eta_c) = 2979.4+-1.5+-1.9 MeV, G(eta_c) = 27.8+-5.1+-3.3 MeV, B(J/psi to eta_c gamma) = (2.34+-0.15+-0.40)%.

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V. V. Anashin, V. M. Aulchenko, E. M. Baldin, A. K. Barladyan, A. Yu. Barnyakov, M. Yu. Barnyakov, S. E. Baru, I. V. Bedny, O. L. Beloborodova, A. E. Blinov, V. E. Blinov, A. V. Bobrov, V. S. Bobrovnikov, A. V. Bogomyagkov, A. E. Bondar, A. R. Buzykaev, S. I. Eidelman, Yu. M. Glukhovchenko, V. V. Gulevich, D. V. Gusev, S. E. Karnaev, G. V. Karpov, S. V. Karpov, T. A. Kharlamova, V. A. Kiselev, S. A. Kononov, K. Yu. Kotov, E. A. Kravchenko, V. F. Kulikov, G. Ya. Kurkin, E. A. Kuper, E. B. Levichev, D. A. Maksimov, V. M. Malyshev, A. L. Maslennikov, A. S. Medvedko, O. I. Meshkov, A. I. Milstein, S. I. Mishnev, I. I. Morozov, N. Yu. Muchnoi, V. V. Neufeld, S. A. Nikitin, I. B. Nikolaev, I. N. Okunev, A. P. Onuchin, S. B. Oreshkin, I. O. Orlov, A. A. Osipov, S. V. Peleganchuk, S. G. Pivovarov, P. A. Piminov, V. V. Petrov, A. O. Poluektov, I. N. Popkov, G. E. Pospelov, V. G. Prisekin, A. A. Ruban, V. K. Sandyrev, G. A. Savinov, A. G. Shamov, D. N. Shatilov, B. A. Shwartz, E. A. Simonov, S. V. Sinyatkin, Yu. I. Skovpen, A. N. Skrinsky, V. V. Smaluk, A. M. Sukharev, E. V. Starostina, A. A. Talyshev, V. A. Tayursky, V. I. Telnov, Yu. A. Tikhonov, K. Yu. Todyshev, G. M. Tumaikin, Yu. V. Usov, A. I. Vorobiov, A. N. Yushkov, V. N. Zhilich, V. V. Zhulanov, A. N. Zhuravlev. 2010-02-10. Measurement of J/psi to eta_c gamma at KEDR. https://doi.org/10.1088/1674-1137/34/6/035

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