$\omega -\pi {\gamma }^{\ast }$ transition form factor in proton-proton collisions

Abstract

Dalitz decays of $\omega$ and $\rho$ mesons, $\omega \to {\pi }^0{\gamma }^{\ast }\to {\pi }^0{e}^{+}{e}^{-}$ and ${\rho }^0\to {\pi }^0{\gamma }^{\ast }\to {\pi }^0{e}^{+}{e}^{-}$, produced in $pp$ collisions are calculated within a covariant effective meson-nucleon theory. We argue that the $\omega$ transition form factor $F_{\omega \to {\pi }^0{\gamma }^{\ast }}$ 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.