1. MEASUREMENT OF $\mathcal{B}(J/\psi\to \eta_{{\rm c}}\gamma)$ AT KEDR
- Author
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E. A. Kravchenko, Anton Poluektov, V.G. Prisekin, S.A. Kononov, K. Yu Todyshev, S.G. Pivovarov, Yu.M. Glukhovchenko, Yu. I. Skovpen, V.N. Zhilich, Oleg Meshkov, Valery I. Telnov, I.N. Okunev, A. Yu. Barnyakov, A. S. Medvedko, E.A. Kuper, E. A. Simonov, V. F. Kulikov, V. V. Petrov, A.A. Osipov, V.K. Sandyrev, A. I. Milstein, S. I. Mishnev, A. P. Onuchin, G.Ya. Kurkin, V. E. Blinov, G. V. Karpov, Evgeny Levichev, S.A. Nikitin, S.I. Eidelman, Yu. A. Tikhonov, A.G. Shamov, Yu. V. Usov, N. Yu. Muchnoi, A. Bobrov, A.E. Bondar, M.Yu. Barnyakov, Evgenii Baldin, D. A. Maksimov, Alexey Maslennikov, V. A. Kiselev, V. A. Tayursky, Sergey Peleganchuk, A.N. Skrinsky, G. E. Pospelov, A. I. Vorobiov, A. E. Blinov, A.A. Ruban, A. R. Buzykaev, Dmitry Shatilov, I. Bedny, I. B. Nikolaev, D. V. Gusev, S.E. Baru, Victor Smaluk, V. V. Gulevich, A.K. Barladyan, A. N. Yushkov, Sergey Sinyatkin, S.V. Karpov, Pavel Piminov, B.A. Shwartz, V. M. Aulchenko, A.M. Sukharev, V.V. Anashin, G.A. Savinov, S.B. Oreshkin, A. N. Zhuravlev, G.M. Tumaikin, A. V. Bogomyagkov, K.Yu. Kotov, I. I. Morozov, I. O. Orlov, Tatyana Kharlamova, O. L. Beloborodova, Vladimir Zhulanov, I.Yu. Basok, Sergey Karnaev, Alexey Talyshev, Andrey Sokolov, V. M. Malyshev, E.V. Starostina, V.V. Neufeld, and V. S. Bobrovnikov
- Subjects
Physics ,Particle physics ,Photon ,Branching fraction ,law ,Radiative decay ,Analytical chemistry ,Collider ,law.invention - Abstract
We present a study of the inclusive photon spectrum from 6.3 million J/ψ decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/ψ → ηcγ, ηc width and mass. Taking into account an asymmetric photon line shape we obtain: Mηc = (2978.1 ± 1.4 ± 2.0) MeV/c2, Γηc = (43.5 ± 5.4 ± 15.8) MeV, [Formula: see text].
- Published
- 2011