Speaker
Prof.
Evgeny Solodov
(BINP)
Description
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.
Primary author
Prof.
Evgeny Solodov
(BINP)
