English

Measurement of \psi(3770) parameters

High Energy Physics - Experiment 2012-04-30 v2

Abstract

We report the final results of a study of the \psi(3770) meson using a data sample collected with the KEDR detector at the VEPP-4M electron-positron collider. The data analysis takes into account the interference between the resonant and nonresonant DDˉD\bar{D} production, where the latter is related to the nonresonant part of the energy-dependent form factor FDF_D. The vector dominance approach and several empirical parameterizations have been tried for the nonresonant FD\NR(s)F_D^{\NR}(s). Our results for the mass and total width of \psi(3770) are M = 3779.2 ^{+1.8}_{-1.7} ^{+0.5}_{-0.7} ^{+0.3}_{-0.3} MeV, \Gamma =24.9 ^{+4.6}_{-4.0} ^{+0.5}_{-0.6} ^{+0.2}_{-0.9} MeV, where the first, second and third uncertainties are statistical, systematic and model, respectively. For the electron partial width two possible solutions have been found: (1) \Gamma_{ee} = 154 ^{+79}_{-58} ^{+17}_{-9} ^{+13}_{-25} eV, (2) \Gamma_{ee} = 414 ^{+72}_{-80} ^{+24}_{-26} ^{+90}_{-10} eV. Our statistics are insufficient to prefer one solution to another. The solution (2) mitigates the problem of non-DDˉD\bar{D} decays but is disfavored by potential models. It is shown that taking into account the resonance--continuum interference in the near-threshold region affects resonance parameters, thus the results presented can not be directly compared with the corresponding PDG values obtained ignoring this effect.

Keywords

Cite

@article{arxiv.1109.4205,
  title  = {Measurement of \psi(3770) parameters},
  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:1109.4205},
  year   = {2012}
}