Observation of a fine structure in e+e−→hadrons production at the nucleon-antinucleon threshold
Date
2019
Authors
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.
Journal Title
Journal ISSN
Volume Title
Publisher
Physics Letters B
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. The very fast rise with about 1 MeV width has been observed in the e+e−→p¯p cross section. A sharp drop in the e+e−→3(π+π−) cross section has been confirmed and found to have a less than 2 MeV width, in agreement with the observed fast rise of the e+e−→p¯p cross section. For the first 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.
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Citation
Akhmetshin, R.R., Amirkhanov, A.N., Anisenkov, A.V., Aulchenko, V.M., Banzarov, V.Sh., Bashtovoy, N.S., … Yudin, Y.V.(2019). Observation of a fine structure in e+e−→hadrons production at the nucleon-antinucleon threshold. Physics Letters B, 794, 64-68. https://doi.org/10.1016/j.physletb.2019.05.032