6533b7d4fe1ef96bd1261cb2

RESEARCH PRODUCT

Eta photoproduction from nuclei

subject

description

Low-energy eta photoproduction from complex nuclei is investigated in a distorted wave impulse approximation (DWIA) framework carried out in momentum spaces. The elementary operator is fixed by the hadronic reactions πN→πN, πN→ππN and π−p→ηn as well as the process γN→πN to constrain the electromagnetic vertex. The resonances S11(1535), P11(1440) and D13(I520) are used to generate s-, p- and d-wave interactions. This coupled channels approach fulfils unitarity and allows the prediction of γp→ηp cross sections. 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 eta production is dominated by the D13(1520) isobar while spin-flip transitions to excited nuclear states are sensitive to the S11(1535) resonance. The influence of the P11(1440) appears to be marginal. Predictions are given for coherent production on 4He, 12C and 40Ca, as well as incoherent production on 6Li, 10B, 12C and 14N.