46 research outputs found

    Measurement of the e+eβˆ’β†’K+Kβˆ’Ο€+Ο€βˆ’e^+e^- \to K^+K^-\pi^+\pi^- cross section with the CMD-3 detector at the VEPP-2000 collider

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    The process e+eβˆ’β†’K+Kβˆ’Ο€+Ο€βˆ’e^+e^- \to K^+K^-\pi^+\pi^- has been studied in the center-of-mass energy range from 1500 to 2000\,MeV using a data sample of 23 pbβˆ’1^{-1} collected with the CMD-3 detector at the VEPP-2000 e+eβˆ’e^+e^- collider. Using about 24000 selected events, the e+eβˆ’β†’K+Kβˆ’Ο€+Ο€βˆ’e^+e^- \to K^+K^-\pi^+\pi^- cross section has been measured with a systematic uncertainty decreasing from 11.7\% at 1500-1600\,MeV to 6.1\% above 1800\,MeV. A preliminary study of K+Kβˆ’Ο€+Ο€βˆ’K^+K^-\pi^+\pi^- production dynamics has been performed

    Measurement of the neutron timelike electromagnetic form factor with the SND detector

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    The results of the measurement of the e+eβˆ’β†’nnΛ‰e^+e^- \to n \bar{n} cross section and effective neutron timelike form factor are presented. The data taking was carried out in 2020-2021 at the VEPP-2000 e+eβˆ’e^+e^- collider in the center-of-mass energy range from 1891 to 2007 MeV. The general purpose nonmagnetic detector SND is used to detect neutron-antineutron events. The event selection is performed using the time-of-flight technique. The measured cross section is 0.4-0.6 nb. The neutron form factor in the energy range under study varies from 0.3 to 0.2.Comment: 13 pages, 8 figure

    Study of the process e+eβˆ’β†’Ο‰Ο€0β†’Ο€+Ο€βˆ’Ο€0Ο€0e^+e^- \to \omega\pi^0 \to \pi^+\pi^-\pi^0\pi^0 in the energy range 1.05βˆ’2.001.05-2.00 GeV with SND

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    The process e+eβˆ’β†’Ο‰Ο€0β†’Ο€+Ο€βˆ’Ο€0Ο€0e^+e^- \to \omega\pi^0 \to \pi^+\pi^-\pi^0\pi^0 is studied in the center-of-mass energy region 1.05βˆ’2.001.05-2.00 GeV using data with an integral luminosity of about 35 pbβˆ’1^{-1} collected with the SND detector at the VEPP-2000 e+eβˆ’e^+e^- collider. In the energy range under study, the value of the measured Born cross section varies from 0.7 to 18 nb. The statistical uncertainty of the cross section is 2βˆ’232-23%, while the systematic uncertainty is in the range of 3.0βˆ’14.23.0-14.2%. The results are consistent with previous measurements but have better accuracy.Comment: 13 pages, 11 figure

    Study of the process e+eβˆ’β†’Ξ·Ξ³β†’7Ξ³e^+e^-\to\eta\gamma\to 7\gamma in the energy range s\sqrt{s} = 1.07 -- 2 GeV

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    The e+eβˆ’β†’Ξ·Ξ³e^+e^-\to\eta\gamma cross section is measured in the center-of-mass energy range from 1.07 to 2.00 GeV in the decay channel Ξ·β†’3Ο€0\eta\to 3\pi^0, Ο€0β†’Ξ³Ξ³\pi^0\to\gamma\gamma. The data set with an integrated luminosity of 242 pbβˆ’1^{-1} accumulated in the experiment with the SND detector at the VEPP-2000 e+eβˆ’e^+e^- collider is analyzed.Comment: 12 pages, 3 figures
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