Momentum dependence of the imaginary part of the $\omega$- and ${\eta }^{\prime }$-nucleus optical potential

Abstract

The photoproduction of $\omega$ and ${\eta }^{\prime }$ mesons off carbon and niobium nuclei has been measured as a function of the meson momentum for incident photon energies of 1.2-2.9 GeV at the electron accelerator ELSA. The mesons have been identified via the $\omega \to {\pi }^0\gamma \to 3\gamma$ and ${\eta }^{\prime }\to {\pi }^0{\pi }^0\eta \to 6\gamma$ decays, respectively, registered with the CBELSA/TAPS detector system. From the measured meson momentum distributions the momentum dependence of the transparency ratio has been determined for both mesons. Within a Glauber analysis the in-medium $\omega$ and ${\eta }^{\prime }$ widths and the corresponding absorption cross sections have been deduced as a function of the meson momentum. The results are compared to recent theoretical predictions for the in-medium $\omega$ width and ${\eta }^{\prime }$-N absorption cross sections. The energy dependence of the imaginary part of the $\omega$- and ${\eta }^{\prime }$-nucleus optical potential has been extracted. The finer binning of the present data compared to the existing data allows a more reliable extrapolation towards the production threshold. The modulus of the imaginary part of the ${\eta }^{\prime }$ nucleus potential is found to be about three times smaller than recently determined values of the real part of the ${\eta }^{\prime }$-nucleus potential, which makes the ${\eta }^{\prime }$ meson a suitable candidate for the search for meson-nucleus bound states. For the $\omega$ meson, the modulus of the imaginary part near threshold is comparable to the modulus of the real part of the potential. As a consequence, only broad structures can be expected which makes the observation of $\omega$ mesic states very difficult experimentally.

10 pages, 8 figures

References in corpus (12)

• Indication of a deeply bound compact K-pp state formed in the pp -> p Lambda K+ reaction at 2.85 GeV
• Modification of the $\omega$-Meson Lifetime in Nuclear Matter
• Partial Wave Analysis of the Reaction $p(3.5GeV)+p\to p{K}^{+}\Lambda$ to Search for the "$pp{K}^{-}$" Bound State
• Interaction of vector mesons with baryons and nuclei
• Formation of eta-prime(958)-mesic nuclei by (p,d) reaction
• Observation of the "$K^{-}pp$"-like structure in the $d({\pi }^{+},K^{+})$ reaction at 1.69 GeV/$c$
• Inclusive $\omega$ photoproduction from nuclei and $\omega$ in the nuclear medium
• Feasibility Study of Observing eta' Mesic Nuclei with (p,d) Reaction
• Determination of the eta'-proton scattering length in free space
• Photoproduction of the $\omega$ meson off the proton near threshold
• The spectral function of the omega meson in nuclear matter from a coupled-channel resonance model
• Experimental constraints on the $\omega$-nucleus real potential

Cited by in corpus (15)

• Meson-nucleus potentials and the search for meson-nucleus bound states
• Comprehensive study of mass modifications of light mesons in nuclear matter in the three-flavor extended Linear Sigma Model
• MESON2016 -- Concluding Remarks
• $\eta$ and ${\eta }^{\prime }$ mesons in nuclear matter and nuclei
• Comment on "Search for ${\eta }^{\prime }$ Bound Nuclei in the ${}^{12}\mathrm{C}(\gamma ,p)$ Reaction with Simultaneous Detection of Decay Products"
• Spectral function of the ${\eta }^{\prime }$ meson in nuclear medium based on phenomenological models
• Absorption of $\omega$ and $\varphi$ mesons in the inclusive photonuclear reaction
• Interactions of $\omega$-Mesons in Nuclear Matter and with Nuclei
• Revisiting ${\eta }^{\prime }(958)$ nuclear states
• Nuclear effects on the $\rho$ meson produced in the inclusive photonuclear reaction
• The ${\eta }^{\prime }N$ interaction from the ${\eta }^{\prime }p$ correlation function
• Near-threshold ${\eta }^{\prime }$ meson production in ${\pi }^{-}A$ reactions
• Velocity dependence of the mass modifications of $\rho$ and $\omega$ mesons in 12 GeV $p+A$ reactions
• Backward-angle electroproduction of ${\eta }^{\prime }$ mesons off protons at $W=2.13\text{GeV}$ and $Q^2=0.46{\left(\text{GeV}/c\right)}^2$
• Feasibility of the observation of ${\eta }^{\prime }$ mesic nuclei in the semi-exclusive ${}^{12}$C($p,dp$) reaction