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Observation of a fine structure in e+e− → hadrons production at the nucleon-antinucleon threshold
- Source :
- Physics Letters B, Vol 794, Iss, Pp 64-68 (2019)
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 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 about 1 MeV width has been observed in the $e^+e^- \to p\bar p$ cross section. A sharp drop in the $e^+e^- \to 3(\pi^+\pi^-)$ cross section has been confirmed and found to have a less than 2 MeV width, in agreement with the observed fast rise of the $e^+e^- \to p\bar p$ cross section. For the first time a similar sharp drop is demonstrated in the $e^+e^- \to K^+K^-\pi^+\pi^-$ cross section. The behavior of the $e^+e^- \to 3(\pi^+\pi^-),~ K^+K^-\pi^+\pi^-$ 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 $e^+e^- \to 2(\pi^+\pi^-)$ cross section.<br />Comment: 7 pages, 5 figures
Details
- ISSN :
- 03702693
- Volume :
- 794
- Database :
- OpenAIRE
- Journal :
- Physics Letters B
- Accession number :
- edsair.doi.dedup.....dd0a169f49c1cf0084f85dedc606cb27