6533b855fe1ef96bd12b1109

RESEARCH PRODUCT

Coherent and incoherent η-photoproduction from nuclei

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Abstract Elastic and inelastic η-photoproduction from complex nuclei is studied in a distorted-wave impulse approximation (DWIA) framework. The elementary operator is obtained by using a dynamical model which employs the reactions π N→ π N, π N→ ππ N and π − p→ η n to fix the hadronic vertex as well as the isobar propagators and the process γ N→ π N to constrain the electromagnetic vertex. The nuclear structure input for the inelastic transitions has been extracted from electron-scattering form factors. The η final-state interaction has been included via a simple optical potential using the ηN t -matrix as an input. We find that coherent η-production is dominated by the D 13 (1520) isobar while spin-flip transitions to excited nuclear states are sensitive to the S 11 (1535) resonance. Predictions are given for coherent production on 4 He, 12 C and 40 Ca, as well as incoherent production on 6 Li, 10 B and 12 C.