Speaker
Alexey Guskov
(Joint Inst. for Nuclear Research (RU))
Description
The electric (${\alpha}_{\pi}$) and the magnetic (${\beta}_{\pi}$) polarisabilities are fundamental properties of the pion characterising the rigidity of its internal structure as a complex QCD system. They have been precisely measured at the
COMPASS experiment at CERN with a ${\pi}^{-}$ beam of 190~GeV/c
assuming ${\alpha}_{\pi}+{\beta}_{\pi}=0$. Muons of the same
momentum were used for controlling of systematic effects. The
obtained result ${\alpha}_{\pi}=-{\beta}_{\pi}=(2.0\pm 0.6_{stat.}\pm
0.7_{syst.})\times 10^{-4} fm^3$ is in agreement with
the prediction of the Chiral Perturbation Theory.
Primary author
Alexey Guskov
(Joint Inst. for Nuclear Research (RU))
