Nucleon electric and magnetic polarizabilities in holographic QCD

We analyze the resonance contributions to the generalized Baldin sum rule, namely the sum of the generalized electric and magnetic nucleon polarizabilities <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>α</a:mi></a:mrow><a:mrow><a:mi>E</a:mi></a:mrow></a:msub><a:mo stretchy="false">(</a:mo><a:msup><a:mrow><a:mi>Q</a:mi></a:mrow><a:mrow><a:mn>2</a:mn></a:mrow></a:msup><a:mo stretchy="false">)</a:mo></a:mrow></a:math> and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:mi>β</e:mi><e:mi>M</e:mi></e:msub><e:mo stretchy="false">(</e:mo><e:msup><e:mi>Q</e:mi><e:mn>2</e:mn></e:msup><e:mo stretchy="false">)</e:mo></e:math>, within the holographic QCD model by Witten, Sakai, and Sugimoto (WSS). In particular, we account for the contributions from the first low-lying nucleon resonances with spin-<i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mrow><i:mn>1</i:mn><i:mo>/</i:mo><i:mn>2</i:mn></i:mrow></i:math> and spin-<k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:mrow><k:mn>3</k:mn><k:mo>/</k:mo><k:mn>2</k:mn></k:mrow></k:math> and both parities. After having extrapolated the WSS model parameters to fit experimental data on baryonic observables, we compare our findings with alternative predictions in literature, finding a qualitative agreement with all of them. Moreover, at least for the proton case, where data are available, our results are in qualitative accordance with resonance contributions extracted from experimental nucleon-resonance helicity amplitudes. Published by the American Physical Society 2024