$\omega - \pi\gamma^*$ transition form factor in proton-proton collisions

Abstract

Dalitz decays of $\omega$ and $\rho$ mesons, $\omega\to \pi^0\gamma^*\to\pi^0 e^+e^-$ and $\rho^0\to \pi^0\gamma^*\to\pi^0 e^+e^-$, produced in $pp$ collisions are calculated within a covariant effective meson-nucleon theory. We argue that the $\omega$ transition form factor $F_{\omega\to \pi^0\gamma^*}$ is experimentally accessible in a fairly model independent way in the reaction $pp \to pp \pi^0 e^+ e^-$ for invariant masses of the $\pi^0 e^+ e^-$ subsystem near the $\omega$ pole. Numerical results are presented for the intermediate energy kinematics of envisaged HADES experiments.