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ISSN - 03702693, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2002, vol. 527, p. 161-172

Measurement of e+e- → π+π- cross-section with CMD-2 around ρ-meson

Akhmetshin R. R., Anashkin E. V., Arbuzov A. B., Aulchenko V. M., Banzarov V. Sh, Barkov L. M., Baru S. E., Bashtovoy N. S., Bondar A. E., Bondarev D. V., Bragin A. V., Chernyak D. V., Dhawan S., Eidelman S. I., Fedotovich G. V., Gabyshev N. I., Gorbachev D. A., Grebenuk A. A., Grigoriev D. N., Hughes V. W., Ignatov F. V., Karpov S. V., Kazanin V. F., Khazin B. I., Koop I. A., Krokovny P. P., Kuraev E. A., Kurdadze L. M., Kuzmin A. S., Logashenko I. B., Lukin P. A., Lysenko A. P., Mikhailov K. Yu, Miller J. P., Milstein A. I., Nesterenko I. N., Okhapkin V. S., Polunin A. A., Popov A. S., Purlatz T. A., Roberts B. L., Root N. I., Ruban A. A., Ryskulov N. M., Shamov A. G., Shatunov Yu M., Shwartz B. A., Sibidanov A. L., Sidorov V. A., Skrinsky A. N., Smakhtin V. P., Snopkov I. G., Solodov E. P., Stepanov P. Yu, Sukhanov A. I., Thompson J. A., Titov V. M., Yudin Yu Y., Zverev S. G.

The cross-section of the process e+e- → π+π- has been measured using about 11 4000 events collected by the CMD-2 detector at the VEPP-2M e+e- collider in the center-of-mass energy range from 0.61 to 0.96 GeV. Results of the pion form factor determination with a 0.6% systematic uncertainty are presented. The following values of the ρ- and ω-meson parameters were found: Mρ = (776.09 ± 0.81) MeV, Γρ = (144.46 ± 1.55) MeV, Γ(ρ → e+e-) = (6.86 ± 0.12) keV, Br(ω → π+π- = (1.33 ± 0.25)%. Implications for the hadronic contribution to the muon anomalous magnetic moment are discussed. © 2002 Elsevier Science B.V. All rights reserved.