1. Measurement of the $e^+e^-\toπ^+π^-$ cross section from threshold to 1.2 GeV with the CMD-3 detector
- Author
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3 Collaboration, Ignatov, F. V., Akhmetshin, R. R., Amirkhanov, A. N., Anisenkov, A. V., Aulchenko, V. M., Bashtovoy, N. S., Berkaev, D. E., Bondar, A. E., Bragin, A. V., Eidelman, S. I., Epifanov, D. A., Epshteyn, L. B., Erofeev, A. L., Fedotovich, G. V., Gorkovenko, A. O., Grancagnolo, F. J., Grebenuk, A. A., Gribanov, S. S., Grigoriev, D. N., Ivanov, V. L., Karpov, S. V., Kasaev, A. S., Kazanin, V. F., Khazin, B. I., Kirpotin, A. N., Koop, I. A., Korobov, A. A., Kozyrev, A. N., Kozyrev, E. A., Krokovny, P. P., Kuzmenko, A. E., Kuzmin, A. S., Logashenko, I. B., Lukin, P. A., Lysenko, A. P., Mikhailov, K. Yu., Obraztsov, I. V., Okhapkin, V. S., Otboev, A. V., Perevedentsev, E. A., Pestov, Yu. N., Popov, A. S., Razuvaev, G. P., Rogovsky, Yu. A., Ruban, A. A., Ryskulov, N. M., Ryzhenenkov, A. E., Semenov, A. V., Senchenko, A. I., Shatunov, P. Yu., Shatunov, Yu. M., Shebalin, V. E., Shemyakin, D. N., Shwartz, B. A., Shwartz, D. B., Sibidanov, A. L., Solodov, E. P., Talyshev, A. A., Timoshenko, M. V., Titov, V. M., Tolmachev, S. S., Vorobiov, A. I., Zemlyansky, I. M., Zhadan, D. S., Zharinov, Yu. M., Zubakin, A. S., and Yudin, Yu. V.
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High Energy Physics - Experiment (hep-ex) ,FOS: Physical sciences - Abstract
The cross section of the process $e^+e^-\toπ^+π^-$ has been measured in the center of mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on a full dataset collected below 1 GeV during three data taking seasons, corresponding to an integrated luminosity of about 62 pb$^{-1}$. In the dominant $ρ$-resonance region, a systematic uncertainty of 0.7% has been reached. At energies around $ϕ$-resonance the $π^+π^-$ production cross section was measured for the first time with high energy resolution. The forward-backward charge asymmetry in the $π^+π^-$ production has also been measured. It shows the strong deviation from the theoretical prediction based on conventional sQED framework and is in good agreement with GVDM and dispersive-based predictions. The impact of presented results on the evaluation of the hadronic contribution to the anomalous magnetic moment of muon is discussed., 48 pages, 36 figures
- Published
- 2023
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