Coupled-channel contributions to the GDH sum rule from the Jülich–Bonn approach

Abstract We study the Gerasimov–Drell–Hearn (GDH) sum rule within a dynamical coupled-channel approach, the Jülich–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 $$\pi N$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:math> and $$\eta N$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>η</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:math> final states are analyzed simultaneously with older data for the reactions $$\pi N\rightarrow \pi N$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>N</mml:mi> <mml:mo>→</mml:mo> <mml:mi>π</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:math> , $$\eta N$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>η</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:math> , $$K\Lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>K</mml:mi> <mml:mi>Λ</mml:mi> </mml:mrow> </mml:math> , $$K\Sigma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>K</mml:mi> <mml:mi>Σ</mml:mi> </mml:mrow> </mml:math> and $$\gamma p\rightarrow \pi N$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> <mml:mo>→</mml:mo> <mml:mi>π</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:math> , $$\eta N$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>η</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:math> , $$K\Lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>K</mml:mi> <mml:mi>Λ</mml:mi> </mml:mrow> </mml:math> , $$K\Sigma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>K</mml:mi> <mml:mi>Σ</mml:mi> </mml:mrow> </mml:math> . 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.