Determination of the magnetic dipole moment of the rho meson using 4 pion electroproduction data

TL;DR

This paper estimates the magnetic dipole moment of the rho meson using experimental data from electron-positron collisions producing four pions, employing a vector meson dominance model to interpret the results.

Contribution

It provides a novel determination of the rho meson's magnetic dipole moment using 4-pion electroproduction data and a vector meson dominance framework.

Findings

Magnetic dipole moment of rho meson: 2.1 ± 0.5 in e/2m_rho units

Uses preliminary BaBar data for e+ e- to 4π process

Employs a vector meson dominance model with resonance contributions

Abstract

We determine the magnetic dipole moment of the rho meson using preliminary data from the BaBar Collaboration for the $e^+ e^- \to \pi^+ \pi^- 2 \pi^0$ process, in the center of mass energy range from 0.9 to 2.2 GeV. We describe the $\gamma^* \to 4\pi$ vertex using a vector meson dominance model, including the intermediate resonance contributions relevant at these energies. We find that $\mu_\rho = 2.1 \pm 0.5$ in $e/2 m_\rho$ units.