Low energy ω(\to π^0 γ) meson photoproduction in the nucleus

Abstract

The ${\pi }^0\gamma$ invariant mass distribution spectra in the $(\gamma ,{\pi }^0\gamma )$ reaction were measured by TAPS/ELSA collaboration to look for the hadron parameters of the $\omega$ meson in Nb nucleus. We study the mechanism for this reaction, where we consider that the elementary reaction in Nb nucleus proceeds as $\gamma N\to \omega N;\omega \to {\pi }^0\gamma$. The $\omega$ meson photoproduction amplitude for this reaction is extracted from the measured four momentum transfer distribution in the $\gamma p\to \omega p$ reaction. The propagation of the $\omega$ meson and the distorted wave function for the ${\pi }^0$ meson in the final state are described by the eikonal form. The $\omega$ and ${\pi }^0$ mesons nucleus optical potentials, appearing in the $\omega$ meson propagator and ${\pi }^0$ meson distorted wave function respectively, are estimated using the "$t\varrho$" approximation. The effects of pair correlation and color transparency are also studied. The calculated results do not show medium modification for the $\omega$ meson produced in the nucleus for its momentum greater than 200 MeV. It occurs since the $\omega$ meson dominantly decays outside the nucleus. The dependence of the cross section on the final state interaction is also investigated. The broadening of the $\omega$ meson mass distribution spectra is shown to occur due to the large resolution width associated with the detector used in the experiment.

14 pages, 6 figures

References in corpus (11)

• Modification of the rho meson detected by low-mass electron-positron pairs in central Pb-Au collisions at 158 A GeV/c
• NA60 results on the rho spectral function in In-In collisions
• Measurement of Nuclear Transparency for the A(e,e' pi^+) Reaction
• Inclusive $\omega$ photoproduction from nuclei and $\omega$ in the nuclear medium
• Phi-meson photoproduction from nuclei
• First measurement of the rho spectral function in nuclear collisions
• Pionic Color Transparency
• Nuclear transparencies from photoinduced pion production
• Photoproduction of $\omega$ mesons on nuclei near the production threshold
• $\omega (\to {\pi }^{+}{\pi }^{-}{\pi }^0)$ meson photoproduction on proton
• ${\pi }^0\gamma$ invariant mass distribution in the low energy $\gamma p\to \omega p$ reaction

Cited by in corpus (5)

• Broadening of $\rho (\to e^{+}{e}^{-})$ meson produced coherently in the photonuclear reaction
• Absorption of $\omega$ and $\varphi$ mesons in the inclusive photonuclear reaction
• Semihadronic and hadronic decays of ${\rho }^0$ and $\omega$ mesons coherently photoproduced in the isoscalar nuclei
• Nuclear effects on the $\rho$ meson produced in the inclusive photonuclear reaction
• Forward coherent $\omega$ and $\varphi$ mesons production in the photon induced reaction on nuclei