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 (30)

• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• The Cosmological Parameters 2006
• Current correlation functions, QCD sum rules and vector mesons in baryonic matter
• First observation of in-medium modifications of the omega meson
• phi photo-production from Li, C, Al, and Cu nuclei at Egamma=1.5 - 2.4 GeV
• Medium Modification to the $\Omega$-Meson Mass in the Walecka Model
• Hadronic Spectral Functions in Nuclear Matter
• Are eta- and omega-nuclear states bound ?
• Observation of $\rho /\omega$ Meson Modification in Nuclear Matter
• Nuclear bound states of $\omega$ mesons
• Sigma and omega meson propagation in a dense nuclear medium
• The $\varphi$ meson width in the medium from proton induced $\varphi$ production in nuclei
• Omega attenuation in nuclei
• The spectral function of the omega meson in nuclear matter from a coupled-channel resonance model
• Attenuation of phi mesons in gamma A reactions
• Inclusive omega photoproduction off nuclei
• Rho-omega mixing in asymmetric nuclear matter via QCD sum rule approach
• Studying the $\omega$-mass in-medium in $\gamma +A\to {\pi }^0\gamma +X$ reactions
• Coupling of Baryon Resonances to the $N\omega$ channel
• $\omega N$ final state interactions and $\omega$-meson production from heavy-ion collisions
• In-medium spectral change of omega mesons as a probe of QCD four-quark condensate
• Nuclear-matter modification of decay widths in the $\varphi \to e^{+}{e}^{-}$ and $\varphi \to K^{+}{K}^{-}$ channels
• omega-nucleus bound states in the Walecka model
• Nuclear mass number dependence of inclusive production of omega and phi mesons in 12 GeV p + A collisions
• Hadrons in the Nuclear Medium
• Weighted finite energy sum rules for the omega meson in nuclear matter
• Omega meson propagation in dense nuclear matter and collective excitations
• $A$ dependence of the $\gamma$- and $p$-induced production of the $\Lambda (1520)$ from nuclei
• Mesons in the nuclear Medium
• Two pion photoproduction on nucleons and nuclei in the rho and sigma regions

Cited by in corpus (40)

• Transport-theoretical Description of Nuclear Reactions
• Hadron properties in the nuclear medium
• Dilepton Radiation at the CERN Super Proton Synchrotron
• Hadrons in strongly interacting matter
• Meson-nucleus potentials and the search for meson-nucleus bound states
• Modification of the $\omega$-Meson Lifetime in Nuclear Matter
• Absorption of the $\omega$ and $\varphi$ Mesons in Nuclei
• Transparency ratio in γA -> η' A' and the in-medium η' width
• Interaction of vector mesons with baryons and nuclei
• Light Vector Mesons in the Nuclear Medium
• In-medium $\omega$ mass from the $\gamma +Nb\to {\pi }^0\gamma +X$ reaction
• Charm and hidden charm scalar mesons in the nuclear medium
• Momentum dependence of the imaginary part of the $\omega$- and ${\eta }^{\prime }$-nucleus optical potential
• ${\bar{K}}^{\ast }$ meson in dense matter
• Study of possible ωbound states in nuclei with the (γ,p) reaction
• Investigating in-medium properties of the $\omega$ meson via the $\omega \to {\pi }^0\gamma$ decay
• Medium Modifcations of Mesons in Elementary Reactions and Heavy-Ion Collisions
• Nucleon resonances in $\gamma p\to \omega p$ reaction
• Photoproduction of $\omega$ mesons on nuclei near the production threshold
• Experimental approaches for determining in-medium properties of hadrons from photo-nuclear reactions
• Medium Effects in rho-Meson Photoproduction
• Electromagnetic Probes
• A-dependence of phi-meson production in p+A collisions
• Medium Modifications of the Rho Meson in Nuclear Photoproduction
• The width of the omega meson in the nuclear medium
• The $\pi \rho$ Cloud Contribution to the $\omega$ Width in Nuclear Matter
• On the background in the $\gamma p\to \omega ({\pi }^0\gamma )p$ reaction and mixed event simulation
• Analysis of $\omega$ self-energy at finite temperature and density in the real-time formalism
• Low energy ω(\to π^0 γ) meson photoproduction in the nucleus
• Testing the Lambda(1520) hyperon in-medium width in near-threshold proton-nucleus reactions
• Absorption of $\omega$ and $\varphi$ mesons in the inclusive photonuclear reaction
• On the determination of the $D$ meson width in the nuclear medium with the transparency ratio
• 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
• Nuclear medium effects on the ${\bar{K}}^{\ast }$ meson
• Study of in-medium $\omega$ meson properties in Ap, pA and AA collisions
• Selected topics on Hadrons in Nuclei