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Analysis of resonance multipoles from polarization observables in eta photoproduction

L. Tiator·D. Drechsel·G. Knoechlein·C. Bennhold
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Abstract

A combined analysis of new eta photoproduction data for total and differential cross sections, target asymmetry and photon asymmetry is presented. Using a few reasonable assumptions we perform the first model-independent analysis of the E0+, E2- and M2- eta photoproduction multipoles. Making use of the well-known A3/2 helicity amplitude of the D13(1520) state we extract its branching ratio to the eta-N channel, Gamma(eta,N)/Gamma = (0.08 +- 0.01)%. At higher energies, we show that the photon asymmetry is extremely sensitive to small multipoles that are excited by photons in the helicity 3/2 state. The new GRAAL photon asymmetry data at higher energy show a clear signal of the F15(1680) excitation which permits extracting an F15(1680)->eta,N branching ratio of (0.15 +0.35 -0.10)%.

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L. Tiator, D. Drechsel, G. Knoechlein, C. Bennhold. 1999-02-11. Analysis of resonance multipoles from polarization observables in eta photoproduction. https://doi.org/10.1103/physrevc.60.035210

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