The NNbar and multihadron production at the threshold at VEPP2000

E. P. Solodov; R. R. Akhmetshin; A. N. Amirkhanov; A. V. Anisenkov; V. M. Aulchenko; V. Sh. Banzarov; N. S. Bashtovoy; D. E. Berkaev; A. E. Bondar; A. V. Bragin; S. I. Eidelman; D. A. Epifanov; L. B. Epshteyn; A. L. Erofeev; G. V. Fedotovich; S. E. Gayazov; A. A. Grebenuk; S. S. Gribanov; D. N. Grigoriev; F. V. Ignatov; V. L. Ivanov; S. V. Karpov; V. F. Kazanin; I. A. Koop; A. N. Kirpotin; A. A. Korobov; A. N. Kozyrev; E. A. Kozyrev; P. P. Krokovny; A. E. Kuzmenko; A. S. Kuzmin; I. B. Logashenko; P. A. Lukin; K. Yu. Mikhailov; V. S. Okhapkin; Yu. N. Pestov; A. S. Popov; G. P. Razuvaev; Yu. A. Rogovsky; A. A. Ruban; N. M. Ryskulov; A. E. Ryzhenenkov; A. V. Semenov; Yu. M. Shatunov; P. Yu. Shatunov; V. E. Shebalin; D. N. Shemyakin; B. A. Shwartz; D. B. Shwartz; A. L. Sibidanov; V. M. Titov; A. A. Talyshev; A. I. Vorobiov; I. M. Zemlyansky; Yu. V. Yudin

doi:10.1051/epjconf/201921207002

Proceedings

Open Access

EPJ Web of Conferences 212, 07002 (2019)
https://doi.org/10.1051/epjconf/201921207002

The NNbar and multihadron production at the threshold at VEPP2000

E. P. Solodov¹^,2^*, R. R. Akhmetshin¹^,2, A. N. Amirkhanov¹^,2, A. V. Anisenkov¹^,2, V. M. Aulchenko¹^,2, V. Sh. Banzarov¹, N. S. Bashtovoy¹, D. E. Berkaev¹^,2, A. E. Bondar¹^,2, A. V. Bragin¹, S. I. Eidelman¹^,2^,5, D. A. Epifanov¹^,2, L. B. Epshteyn¹^,2^,3, A. L. Erofeev¹^,2, G. V. Fedotovich¹^,2, S. E. Gayazov¹^,2, A. A. Grebenuk¹^,2, S. S. Gribanov¹^,2, D. N. Grigoriev¹^,2^,3, F. V. Ignatov¹^,2, V. L. Ivanov¹^,2, S. V. Karpov¹, V. F. Kazanin¹^,2, I. A. Koop¹^,2, A. N. Kirpotin¹, A. A. Korobov¹^,2, A. N. Kozyrev¹^,3, E. A. Kozyrev¹^,2, P. P. Krokovny¹^,2, A. E. Kuzmenko¹^,2, A. S. Kuzmin¹^,2, I. B. Logashenko¹^,2, P. A. Lukin¹^,2, K. Yu. Mikhailov¹, V. S. Okhapkin¹, Yu. N. Pestov¹, A. S. Popov¹^,2, G. P. Razuvaev¹^,2, Yu. A. Rogovsky¹, A. A. Ruban¹, N. M. Ryskulov¹, A. E. Ryzhenenkov¹^,2, A. V. Semenov¹^,2, Yu. M. Shatunov¹, P. Yu. Shatunov¹, V. E. Shebalin¹^,2, D. N. Shemyakin¹^,2, B. A. Shwartz¹^,2, D. B. Shwartz¹^,2, A. L. Sibidanov¹^,4, V. M. Titov¹, A. A. Talyshev¹^,2, A. I. Vorobiov¹, I. M. Zemlyansky¹ and Yu. V. Yudin¹^,2

¹ Budker Institute of Nuclear Physics, SB RAS, Novosibirsk, 630090, Russia
² Novosibirsk State University, Novosibirsk, 630090, Russia
³ Novosibirsk State Technical University, Novosibirsk, 630092, Russia
⁴ University of Victoria, Victoria, BC, Canada V8W 3P6
⁵ Lebedev Physical Institute RAS, Moscow, 119333, Russia

^* e-mail: solodov@inp.nsk.su

Published online: 17 June 2019

Abstract

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⁻→ pp̅ 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⁻→ pp̅ 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.

© The Authors, published by EDP Sciences, 2019

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