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Multipole Amplitudes of Pion Photoproduction on Nucleons up to 2GeV within Dispersion Relations and Unitary Isobar Model

I. G. Aznauryan
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Abstract

Two approaches for analysis of pion photo- and electroproduction on nucleons in the resonance energy region are checked at $Q^2=0$ using the results of GWU(VPI) partial-wave analysis of photoproduction data. The approaches are based on dispersion relations and unitary isobar model. Within dispersion relations good description of photoproduction multipoles is obtained up to $W=1.8 GeV$. Within unitary isobar model, modified with increasing energy by incorporation of Regge poles, and with unified Breit-Wigner parametrization of resonance contributions, good description of photoproduction multipoles is obtained up to $W=2 GeV$.

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I. G. Aznauryan. 2002-06-14. Multipole Amplitudes of Pion Photoproduction on Nucleons up to 2GeV within Dispersion Relations and Unitary Isobar Model. https://doi.org/10.1103/physrevc.67.015209

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