Speaker
Graziano Venanzoni
(Istituto Nazionale Fisica Nucleare (IT))
Description
We have recently completed and published
the third independent measurement of the e+e- --> pi+pi-(gamma)
cross section below 1 GeV, which is particularly important to
test the Standard Model calculation for the (g-2) of the muon,
where a long standing 3 sigma discrepancy is observed. The previous
measurements, with the photon emitted at small and large angle,
respectively, were normalized to the DAPHNE luminosity using large
angle Bhabha scattering. In the new analysis the pion form factor
is obtained directly from the pi+pi-gamma(gamma)/mu+mu-gamma(gamma)
ratio, with significantly different systematic effects. In the
overlap region there is a very good agreement among different KLOE
measurements.
Author
Fabio Bossi
(Laboratori Nazionali di Frascati (LNF))
