Pion form factor in the range -10 GeV^2 < s < 1 GeV^2

TL;DR

This paper introduces a new theoretical expression for the pion form factor that incorporates meson loops and resonance mixing, accurately describing experimental data over a broad energy range without phenomenological parameters.

Contribution

A novel field-theory-inspired formula for the pion form factor that accounts for meson loops and resonance mixing, improving data description across a wide energy spectrum.

Findings

Accurately describes pion form factor data from -10 GeV^2 to 1 GeV^2

Incorporates meson loops and resonance mixing effects

Eliminates need for phenomenological Blatt-Weisskopf parameter

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 $\pi^+\pi^-$ and $K\bar K$ and the mixing of $\rho(770)$ with heavier $\rho(1450)$ and $\rho(1700)$ resonances. The expression possesses correct analytical properties and describes the data in the wide range of the energy squared $-10{GeV}^2\leq s\leq1$ GeV$^2$ without introducing the phenomenological Blatt -- Weisskopf range parameter $R_\pi$.