Speaker
Mr
Alexandr Korobov
(Budker Institute of Nuclear Physics)
Description
Since 2010 the VEPP-2000 electron-positron collider has been operated at Budker Institute of Nuclear Physics in the center-of-mass (c.m.) energy range from
$\sqrt{s}=320$ MeV to $2000$ MeV. VEPP-2000 has two interaction
regions in which the Cryogenic Magnetic Detector (CMD-3) and the
Spherical Neutral Detector (SND) are installed.
Production of four charged pions in $e^+ e^-$ annihilation has been studied
before with good statistics at the CMD-2 and SND detectors as well as using initial-state radiation (ISR) with BaBar
at which a low systematic uncertainty of about 3% was achieved for the
$e^+ e^- \to \pi^{+}\pi^{-}\pi^{+}\pi^{-}$ cross section in the wide c.m. energy
range.
In this work the cross section of the process $e^+ e^- \to \pi^{+}\pi^{-}\pi^{+}\pi^{-}$ has been measured using an integrated luminosity of 168 pb$^{-1}$ collected with the CMD-3 detector in the c.m. energy range 650-2000 MeV. Also studied
are the internal dynamics of four-pion production. High-precision measurements
of various hadronic cross sections are of great interest in relation with the
problem of the muon anomalous magnetic moment g-2. The $e^+ e^- \to \pi^{+}\pi^{-}\pi^{+}\pi^{-}$ cross section can be also used to test relations between
$e^+e^-$ annihilation and $\tau$ lepton decays based on conservation of vector
current.
Primary author
Mr
Alexandr Korobov
(Budker Institute of Nuclear Physics)
Co-author
Simon Eidelman
(Budker Institute of Nuclear Physics)
