Speaker
Arkadii Kozhevnikov
(Lab. Theoretical Physics, Sobolev Inst. of Mathematics)
Description
Using the field-theory-inspired expression for the pion
electromagnetic form factor $F_\pi$, a good description of the
data in the range $-10<s<1$ GeV$^2$ is obtained upon taking into
account the pseudoscalar-pseudoscalar (PP) loops. When the
vector-pseudoscalar (VP) and the axial vector-pseudoscalar (AP)
loops are taken into account in addition to the PP ones, a good
description of the BABAR data on the reaction
$e^+e^-\to\pi^+\pi^-$ is obtained at energies up to 3 GeV. The
inclusion of the VP and AP loops demands the treatment of the
reactions $e^+e^-\to\omega\pi^0$ and
$e^+e^-\to\pi^+\pi^-\pi^+\pi^-$. This task is also made, with the
SND data on the $\omega\pi^0$ production and the BABAR data on the
$\pi^+\pi^-\pi^+\pi^-$ production, both in $e^+e^-$ annihilation,
upon taking into account $\rho(770)$ and the heavier $\rho(1450)$,
$\rho(1700)$, $\rho(2100)$ resonances. The problems with
inclusion of the VP and AP loops are pointed out and discussed.
Primary author
Arkadii Kozhevnikov
(Lab. Theoretical Physics, Sobolev Inst. of Mathematics)
Co-author
Prof.
Nikolay Achasov
(Sobolev Institute of Mathematics)
