Pion form factor in the range -10 GeV^2 < s < 1 GeV^2
Abstract
Based on the field-theory-inspired approach, a new expression for the pion form factor F_pi is proposed. It takes into account the pseudoscalar meson loops
π
+
π
−
and
K
K
¯
and the mixing of
ρ(770)
with heavier
ρ(1450)
and
ρ(1700)
resonances. The expression possesses correct analytical properties and describes the data in the wide range of the energy squared
−10
GeV
2
≤s≤1
GeV
2
without introducing the phenomenological Blatt -- Weisskopf range parameter
R
π
.