Inclusive $\omega$ photoproduction from nuclei and $\omega$ in the nuclear medium

Abstract

With the aim of extracting information on the shift of the $\omega$ mass in the nuclear medium we analyze data obtained at ELSA from where claims for evidence of a mass shift of the $\omega$ have been made. We develop a Monte Carlo simulation code which takes into account the possible reactions in the experimental set up of $(\gamma A\to {\pi }^0\gamma X)$ in the vicinity of the $\omega$ production region with subsequent $\omega \to {\pi }^0\gamma$ decay. We compare our results with experiment for the distribution of ${\pi }^0\gamma$ invariant masses and conclude that the distribution is compatible with an enlarged $\omega$ width of about 90 MeV at nuclear matter density and no shift in the mass. This change in the width would be compatible with the preliminary results obtained from the transparency ratio in the A dependence of $\omega$ production. The discrepancy of the present conclusions with former claims of an evidence for a shift of the $\omega$ mass stem from a different choice of background which is discussed in the paper.

18 pages, 7 figures

References in corpus (8)

• phi photo-production from Li, C, Al, and Cu nuclei at Egamma=1.5 - 2.4 GeV
• Omega attenuation in nuclei
• The spectral function of the omega meson in nuclear matter from a coupled-channel resonance model
• Nuclear-matter modification of decay widths in the $\varphi \to e^{+}{e}^{-}$ and $\varphi \to K^{+}{K}^{-}$ channels
• Nuclear mass number dependence of inclusive production of omega and phi mesons in 12 GeV p + A collisions
• Weighted finite energy sum rules for the omega meson in nuclear matter
• $A$ dependence of the $\gamma$- and $p$-induced production of the $\Lambda (1520)$ from nuclei
• Mesons in the nuclear Medium

Cited by in corpus (14)

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• ${\bar{K}}^{\ast }$ meson in dense matter
• Study of possible ωbound states in nuclei with the (γ,p) reaction
• Medium Modifcations of Mesons in Elementary Reactions and Heavy-Ion Collisions
• Photoproduction of $\omega$ mesons on nuclei near the production threshold
• A-dependence of phi-meson production in p+A collisions
• On the background in the $\gamma p\to \omega ({\pi }^0\gamma )p$ reaction and mixed event simulation
• Low energy ω(\to π^0 γ) meson photoproduction in the nucleus
• Absorption of phi mesons in near-threshold proton-nucleus reactions
• Mesons in Nuclei: eta and omega mesons
• $\omega (\to {\pi }^{+}{\pi }^{-}{\pi }^0)$ meson photoproduction on proton
• ${\pi }^0\gamma$ invariant mass distribution in the low energy $\gamma p\to \omega p$ reaction
• Photo- and Electron-Production of Mesons on Nucleons and Nuclei