标题： 核子的电和磁极化率在全息QCD中的研究 显示英文标题

标题： Nucleon electric and magnetic polarizabilities in Holographic QCD

摘要： 新型实验结果表明质子广义电极化率在低动量转移平方下出现了与当前理论预测的意外偏差$Q^2$。 受这一谜题的启发，我们在Witten、Sakai和Sugimoto（WSS）的全息QCD模型中，分析了广义电极化率和磁极化率之和的共振贡献$\alpha_E(Q^2)$和$\beta_M(Q^2)$。 特别是，我们考虑了自旋为1/2和3/2以及两种宇称的第一激发核子共振的贡献。 在将WSS模型参数外推以拟合重子可观测量的实验数据后，我们的研究结果表明，仅共振贡献无法解决上述谜题。 此外，至少对于质子情况，当有数据可用时，我们的结果与从实验核子共振螺旋振幅中提取的共振贡献定性一致。 显示英文摘要

摘要： Novel experimental results for the proton generalized electric polarizability, suggest an unexpected deviation from current theoretical predictions at low momentum transfer squared $Q^2$. Motivated by this puzzle, we analyze the resonance contributions to the sum of the generalized electric and magnetic nucleon polarizabilities $\alpha_E(Q^2)$ and $\beta_M(Q^2)$, 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 1/2 and 3/2 and both parities. After having extrapolated the WSS model parameters to fit experimental data on baryonic observables, our findings suggest that the resonance contributions alone do not solve the above-mentioned puzzle. Moreover, at least for the proton case, where data are available, our results are in qualitative agreement with resonance contributions extracted from experimental nucleon-resonance helicity amplitudes.