The NNbar and multihadron production at the threshold at VEPP2000

• Published in: EPJ Web of Conferences 2019, Vol.212, p.7002
• Main Authors: Solodov, E. P., Akhmetshin, R. R., Amirkhanov, A. N., Anisenkov, A. V., Aulchenko, V. M., Banzarov, V. Sh, 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., Gayazov, S. E., Grebenuk, A. A., Gribanov, S. S., Grigoriev, D. N., Ignatov, F. V., Ivanov, V. L., Karpov, S. V., Kazanin, V. F., Koop, I. A., Kirpotin, A. N., Korobov, A. A., Kozyrev, A. N., Kozyrev, E. A., Krokovny, P. P., Kuzmenko, A. E., Kuzmin, A. S., Logashenko, I. B., Lukin, P. A., Mikhailov, K. Yu, Okhapkin, V. S., Pestov, Yu. N., Popov, A. S., Razuvaev, G. P., Rogovsky, Yu. A., Ruban, A. A., Ryskulov, N. M., Ryzhenenkov, A. E., Semenov, A. V., Shatunov, Yu. M., Shatunov, P. Yu, Shebalin, V. E., Shemyakin, D. N., Shwartz, B. A., Shwartz, D. B., Sibidanov, A. L., Titov, V. M., Talyshev, A. A., Vorobiov, A. I., Zemlyansky, I. M., Yudin, Yu. V.
• Format: Article
• Language: English
• Subjects: Antinucleons; Cross-sections; Nucleons; Resonance
• ISSN: 2100-014X; 2101-6275; 2100-014X
• DOI: 10.1051/epjconf/201921207002

A study of hadron production at the nucleon-antinucleon threshold has been performed with the CMD-3 detector at the VEPP-2000 e + e − collider. A very fast rise with an about 1 MeV width has been observed in the e + e − → pp ̅ cross section. A sharp drop in the e + e − → 3(π + π − ) cross section has been con?rmed and found to have a width of less than 2 MeV, in agreement with the observed fast rise of the e + e − → pp ̅ cross section. For the ?rst time a similar sharp drop is demonstrated in the e + e − → K + K − π + π − cross section. The behavior of the e + e − → 3(π + π − ), K + K − π + π − cross sections cannot be explained by an interference of any resonance amplitude with continuum, therefore this phenomenon cannot be due to a narrow near-threshold resonance. No such structure has been observed in the e + e − → 2(π + π − ) cross section.