Measurement of \(\Gamma_{ee}\times\mathcal{B}_{\mu\mu}\) for \(\psi(2S)\) meson

• Published in: arXiv.org 2018-04
• Main Authors: Anashin, V V, Anchugov, O V, Aulchenko, V M, Baldin, E M, Baranov, G N, Barladyan, A K, A Yu Barnyakov, M Yu Barnyakov, Baru, S E, I Yu Basok, Batrakov, A M, Bekhtenev, E A, Blinov, A E, Blinov, V E, Bobrov, A V, Bobrovnikov, V S, Bogomyagkov, A V, Bondar, A E, Buzykaev, A R, Cheblakov, P B, Dorohov, V L, Eidelman, S I, Grigoriev, D N, Glukhov, S A, Karnaev, S E, Karpov, G V, Karpov, S V, K Yu Karukina, Kashtankin, D P, Kharlamova, T A, Kiselev, V A, Kolmogorov, V V, Kononov, S A, K Yu Kotov, Krasnov, A A, Kravchenko, E A, Kudryavtsev, V N, Kulikov, V F, G Ya Kurkin, Kuyanov, I A, Kuper, E A, Levichev, E B, Maksimov, D A, Malyshev, V M, Maslennikov, A L, Meshkov, O I, Mishnev, S I, Morozov, I A, Morozov, I I, N Yu Muchnoi, Nikitin, S A, Nikolaev, I B, Okunev, I N, Onuchin, A P, Oreshkin, S B, Osipov, A A, Ovtin, I V, Peleganchuk, S V, Pivovarov, S G, Piminov, P A, Petrov, V V, Prisekin, V G, Rezanova, O L, Ruban, A A, Savinov, G A, Shamov, A G, Shatilov, D N, Shvedov, D A, Shwartz, B A, Simonov, E A, Sinyatkin, S V, Skrinsky, A N, Sokolov, A V, Sukhanov, D P, Sukharev, A M, Starostina, E V, Talyshev, A A, Tayursky, V A, Telnov, V I, Tikhonov, Yu A, K Yu Todyshev, Tribendis, A G, Tumaikin, G M, Usov, Yu V, Vorobiov, A I, Zhilich, V N, Zhukov, A A, Zhulanov, V V, Zhuravlev, A N
• Format: Article
• Language: English
• Subjects: Channels; Leptons; Luminosity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1801.10362

The product of the electronic width of the \(\psi(2S)\) meson and the branching fraction of its decay to the muon pair was measured in the \(e^{+}e^{-} \to \psi(2S) \to \mu^{+}\mu^{-}\) process using nine data sets corresponding to an integrated luminosity of about 6.5 pb\(^{-1}\) collected with the KEDR detector at the VEPP-4M electron-positron collider: \[ \Gamma_{ee}\times\mathcal{B}_{\mu\mu} = 19.3 \pm 0.3 \pm 0.5 ~\text{eV}. \] Adding the previous KEDR results on hadronic and leptonic channels, the values of the \(\psi(2S)\) electronic width were obtained under two assumptions: either with the assumption of lepton universality \[ \Gamma_{ee} = 2.279 \pm 0.015 \pm 0.042 ~\text{keV} \] or without it, summing up hadronic and three independent leptonic channels: \[ \Gamma_{ee} = 2.282 \pm 0.015 \pm 0.042 ~\text{keV}. \]