Quasifree Eta Photoproduction from Nuclei

Abstract

Quasifree $\eta$ photoproduction from nuclei is studied in the Distorted Wave Impulse Approximation (DWIA). The elementary eta production operator contains Born terms, vector meson and nucleon resonance contributions and provides an excellent description of the recent low energy Mainz measurements on the nucleon. The resonance sector includes the $S_{11}(1535)$, $P_{11}(1440)$ and $D_{13}(1520)$ states whose couplings are fixed by independent electromagnetic and hadronic data. Different models for the $\eta N$ t-matrix are used to construct a simple $\eta A$ optical potential based on a $t\rho$-approximation. We find that the exclusive $A(\gamma ,\eta N)B$ process can be used to study medium modifications of the $N^{\ast }$ resonances, particularly if the photon asymmetry can be measured. The inclusive $A(\gamma ,\eta )X$ reaction is compared to new data obtained on ${}^{12}C$, ${}^{40}Ca$, and is found to provide a clear distinction between different models for the $\eta N$ t-matrix.

30 pages in RevTeX including 14 embedded PS figures; Replaced with revised version. Added more discussion about the imaginary part of the eta optical potential

References in corpus (5)

• The $\eta$NN Coupling in Eta Photoproduction
• Near-Threshold Production of $\eta$-Mesons
• pi N --> eta N and eta N --> eta N partial wave T-matrices in a coupled, three channel model
• Off-shell Behavior of the $\pi -\eta$ Mixing Amplitude
• Pion interaction with the trinucleon up to the eta production threshold

Cited by in corpus (11)

• Quasifree Kaon Photoproduction on Nuclei
• Photoproduction of pions and etas in nuclei
• The energy dependence of the in-medium $\eta N$ cross section evaluated from $\eta$-photoproduction
• Quasifree kaon-photoproduction from nuclei in a relativistic approach
• Relativistic Calculations for Incoherent Photoproduction of Eta Mesons
• Relativistic Calculations for the Exclusive Photoproduction of Eta Mesons from Complex Nuclei
• Higher Nucleon Resonances in Exclusive $(\gamma ,\pi N)$ Reactions on Nuclei
• Kaon Electromagnetic Production on Nuclei
• Resonance dynamics in the coherent $\eta$ meson production in the $(p,p^{\prime })$ reaction on the spin-isospin saturated nucleus
• Non-locality and Medium Effects in the Exclusive Photoproduction of Eta Mesons on Nuclei
• Quasifree eta photoproduction from nuclei and medium modifications of resonances