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arXiv · 2508.00598

Coupled-channel contributions to the GDH sum rule from the J\"ulich-Bonn approach

Carolin Schneider·Deborah Rönchen·Christoph Hanhart·Ulf-G. Meißner
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Abstract

We study the Gerasimov-Drell-Hearn (GDH) sum rule within a dynamical coupled-channel approach, the J\"ulich-Bonn model for light baryon resonances based on fits to an extensive data base of pion and photon induced data. Recently published photoproduction data for different observables with $\pi N$ and $\eta N$ final states are analyzed simultaneously with older data for the reactions $\pi N\to \pi N$, $\eta N$, $K\Lambda$, $K\Sigma$ and $\gamma p\to\pi N$, $\eta N$, $K\Lambda$, $K\Sigma$. The impact of the new data on the resonance spectrum is investigated and the contribution of the individual channels to the GDH integral is determined.

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Carolin Schneider, Deborah Rönchen, Christoph Hanhart, Ulf-G. Meißner. 2025-08-01. Coupled-channel contributions to the GDH sum rule from the J\"ulich-Bonn approach. https://doi.org/10.1140/epja%2Fs10050-025-01719-x

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