Vector meson photoproduction studied in its radiative decay channel

Abstract

We provide an analysis of vector meson photoproduction in the channel of the vector meson decaying into a pseudoscalar meson plus a photon, i.e. $V\to Pγ$. It is shown that non-trivial kinematic correlations arise from the measurement of the $Pγ$ angular distributions in the overall c.m. system in comparison with those in the vector-meson-rest frame. In terms of the vector meson density matrix elements, the implication of such kinematic correlations in the measurement of polarization observables is discussed. For the $ω$ meson production, due to its relatively large branching ratios for $ω\toπ^0γ$, additional events from this channel may enrich the information about the reaction mechanism and improve the statistics of the recent measurement of polarized beam asymmetries by the GRAAL Collaboration. For $ϕ\to ηγ$, $ρ\to πγ$, and $K^*\to Kγ$, we expect that additional information about the spin structure of the vector meson production vertex can be derived.