Measurement of main parameters of the \psi(2S) resonance
Abstract
A high-precision determination of the main parameters of the \psi(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the \psi(2S) we obtained the mass value M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the electron partial width by the branching fraction into hadrons \Gamma_{ee}*B_{h} = 2.233 +- 0.015 +- 0.037 +- 0.020 keV. The third error quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the \psi(2S): \Gamma_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV, \Gamma = 296 +- 2 +- 8 +- 3 keV. These results are consistent with and more than two times more precise than any of the previous experiments.
Keywords
Cite
@article{arxiv.1109.4215,
title = {Measurement of main parameters of the \psi(2S) resonance},
author = {V. V. Anashin and V. M. Aulchenko and E. M. Baldin and A. K. Barladyan and A. Yu. Barnyakov and M. Yu. Barnyakov and S. E. Baru and I. Yu. Basok and O. L. Beloborodova and A. E. Blinov and V. E. Blinov and A. V. Bobrov and V. S. Bobrovnikov and A. V. Bogomyagkov and A. E. Bondar and A. R. Buzykaev and S. I. Eidelman and D. N. Grigoriev and Yu. M. Glukhovchenko and V. V. Gulevich and D. V. Gusev and S. E. Karnaev and G. V. Karpov and S. V. Karpov and T. A. Kharlamova and V. A. Kiselev and V. V. Kolmogorov and S. A. Kononov and K. Yu. Kotov and E. A. Kravchenko and V. N. Kudryavtsev and V. F. Kulikov and G. Ya. Kurkin and E. A. Kuper and E. B. Levichev and D. A. Maksimov and V. M. Malyshev and A. L. Maslennikov and A. S. Medvedko and O. I. Meshkov and S. I. Mishnev and I. I. Morozov and N. Yu. Muchnoi and V. V. Neufeld and S. A. Nikitin and I. B. Nikolaev and I. N. Okunev and A. P. Onuchin and S. B. Oreshkin and I. O. Orlov and A. A. Osipov and S. V. Peleganchuk and S. G. Pivovarov and P. A. Piminov and V. V. Petrov and A. O. Poluektov and V. G. Prisekin and A. A. Ruban and V. K. Sandyrev and G. A. Savinov and A. G. Shamov and D. N. Shatilov and B. A. Shwartz and E. A. Simonov and S. V. Sinyatkin and A. N. Skrinsky and V. V. Smaluk and A. V. Sokolov and A. M. Sukharev and E. V. Starostina and A. A. Talyshev and V. A. Tayursky and V. I. Telnov and Yu. A. Tikhonov and K. Yu. Todyshev and G. M. Tumaikin and Yu. V. Usov and A. I. Vorobiov and A. N. Yushkov and V. N. Zhilich and V. V. Zhulanov and A. N. Zhuravlev},
journal= {arXiv preprint arXiv:1109.4215},
year = {2012}
}