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.

arXiv comment14 pages, 6 figures

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Cited by in corpus (6)

• Investigating in-medium properties of the $\omega$ meson via the $\omega \to {\pi }^0\gamma$ decay
• 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