Investigating in-medium properties of the $\omega$ meson via the $\omega \to {\pi }^0\gamma$ decay

Abstract

We investigate the feasibility of studying in-medium properties of the $\omega$ meson in photoproduction experiments via the decay $\omega \to {\pi }^0\gamma$. We use the GiBUU transport model to compare different methods of obtaining in-medium information, such as the invariant mass spectrum, transparency ratio, excitation function and momentum spectrum. We show that the final-state interaction of the pion poses a major obstacle for the interpretation of the invariant mass spectrum. The other three observables turn out to be fairly independent of final-state interactions and thus can give access to the $\omega$'s in-medium properties.

Comments: 8 pages, 6 figures