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ISSN - 10637761, EISSN - 10906509, Journal of Experimental and Theoretical Physics, 2005, vol. 101, p. 1053-1070

Study of the Process e+e- → π+π - in the energy region 400 < √s < 1000 MeV

Achasov M. N., Beloborodov K. I., Berdyugin A. V., Bogdanchikov A. G., Bozhenok A. V., Bukin A. D., Bukin D. A., Dimova T. V., Druzhinin V. P., Golubev V. B., Koop I. A., Korol A. A., Koshuba S. V., Lysenko A. P., Otboev A. V., Pakhtusova E. V., Serednyakov S. I., Shatunov Yu M., Sidorov V. A., Silagadze Z. K., Skrinsky A. N., Tikhonov Yu A., Vasiljev A. V.

The cross section of the process e+e- → π+π- was measured in the spherical neutral detector experiment at the VEPP-2M collider in the energy region 400 < s< 1000 MeV. This measurement was based on about 12.4 × 106 selected collinear events, which include 7.4 × 106 e+e - → e+e-, 4.5 × 106 e+e- → π+π-, and 0.5 × 106 e+e- → μ+μ - selected events. The systematic uncertainty of cross section determination is 1.3%. The ρ-meson parameters were determined as m ρ = 774.9 ± 0.4 ± 0.5 MeV, Γρ = 146.5 ± 0.8 ± 1.5 MeV, and σ(ρ → π+π-) = 1220 ± 7 ± 16 nb and the parameters of the G-parity suppressed decay ω → π+π - as σ(ω → π+π-) = 29.9 ± 1.4 ± 1.0 nb and φρω = 113.5 ± 1.3 ± 1.7°. © 2005 Pleiades Publishing, Inc.