Measurement of J/ψ→γηc decay rate and ηc parameters at KEDR

• DOI: 10.1016/j.physletb.2014.09.064
• Publication Date: 2014-10-08T02:12:56Z
• Authors: V.V. Anashin; V.M. Aulchenko; E.M. Baldin; A.K. Barladyan; A.Yu. Barnyakov; M.Yu. Barnyakov; S.E. Baru; I.Yu. Basok; I.V. Bedny; 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; 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; G.E. Pospelov; V.G. Prisekin; O.L. Rezanova; A.A. Ruban; V.K. Sandyrev; G.A. Savinov; A.G. Shamov; D.N. Shatilov; B.A. Shwartz; E.A. Simonov; S.V. Sinyatkin; A.N. Skrinsky; V.V. Smaluk; A.V. Sokolov; 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
• Keywords: Physics; QC1-999; 0103 physical sciences; 01 natural sciences

Using the inclusive photon spectrum based on a data sample collected at the J/ψ peak with the KEDR detector at the VEPP-4M e+e− collider, we measured the rate of the radiative decay J/ψ→γηc as well as ηc mass and width. Taking into account an asymmetric photon lineshape we obtained Γγηc0=2.98±0.18−0.33+0.15keV, Mηc=2983.5±1.4−3.6+1.6MeV/c2, Γηc=27.2±3.1−2.6+5.4MeV. Keywords: Charmonium, Radiative decays