Plenary Session VII – Chair: T. NakanoNo Access

S₁₁ RESONANCES IN A COUPLED-CHANNEL DYNAMICAL MODEL

Physics Department and National Center for Theoretical Sciences at Taipei, National Taiwan University, Taipei 10617, Taiwan, ROC

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GUAN-YEU CHEN

Physics Department and National Center for Theoretical Sciences at Taipei, National Taiwan University, Taipei 10617, Taiwan, ROC

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SABIT S. KAMALOV

Physics Department and National Center for Theoretical Sciences at Taipei, National Taiwan University, Taipei 10617, Taiwan, ROC

Permanent address: Bogoliubov Laboratory for Theoretical Physics, JINR, Dubna, Russia.

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L. TIATOR

Institut für Kernphysik, Universität Mainz, Mainz 55099, Germany

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, and

D. DRECHSEL

Institut für Kernphysik, Universität Mainz, Mainz 55099, Germany

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https://doi.org/10.1142/S0217751X0502313XCited by:2 (Source: Crossref)

Abstract

A self-consistent analysis of pion scattering and pion photoproduction within a coupled channels dynamical model is presented. The results indicate the existence of a third and a fourth S₁₁ resonance with the masses 1846±47 and 2113±70 MeV. In the case of pion photoproduction, we found that background contributions to the imaginary part of the S-wave multipole become large and negative in the region of the S₁₁(1535) resonance. Due to this fact, much larger resonance contributions are required in order to explain the results of the recent multipole analysis. For the first S₁₁(1535) resonance we obtain a value of 72±2×10^-3GeV^-1/2 for the electromagnetic helicity amplitude A_1/2.