$πωρ$ vertex in nuclear matter

Abstract

Medium modifications of the $πωρ$ vertex are analyzed in context of the $ω\to π^0 γ^\ast$ and $ρ\to πγ^\ast$ decays in nuclear matter. A relativistic hadronic model with mesons, nucleons, and $Δ(1232)$ isobars is applied. A substantial increase of the widths for the decays $ω\to π^0 γ^\ast$ and $ρ\to πγ^\ast$ is found for photon virtualities in the range $0.3-0.6$GeV. This enhancement has a direct importance for the description of dilepton yields from dalitz decays in relativistic heavy-ion collisions.