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

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 ${\gamma }^{\ast }\to 4\pi$ 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 $e/2m_{\rho }$ units.

Comments: 18 pages, 6 figures. Extended version including details, one new figure, one table and references added, results unchanged