标题： π介子的电子产生和广义GDH求和规则 显示英文标题

标题： Pion electroproduction on the nucleon and the generalized GDH sum rule

摘要： 最近开发的幺正单极模型（MAID）的结果在共振区域中给出了自旋不对称性、结构函数和相关求和规则。 该模型很好地描述了低于Wcm = 2 GeV的共振区域中单π介子光致和电致产生目前可用的数据。 该模型基于玻恩项和共振贡献，每个分波的多极子以规范不变且幺正的方式构建。 η产生以类似方式包含，而多π介子和更高通道的贡献则通过与总截面比较以及简单的现象学假设进行建模。 我们对能量加权积分的评估在质子上具有良好一致性，但在中子上显示出较大差异。 显示英文摘要

摘要： Results of the recently developed unitary isobar model (MAID) are presented for the spin asymmetries, structure functions and relevant sum rules in the resonance region. The model describes the presently available data for single-pion photo- and electroproduction in the resonance region below Wcm = 2 GeV very well. It is based on Born terms and resonance contributions, and the respective multipoles are constructed in a gauge-invariant and unitary way for each partial wave. The eta production is included in a similar way, while the contribution of more-pion and higher channels is modeled by comparison with the total cross sections and simple phenomenological assumptions. Our evaluation of the energy-weighted integrals is in good agreement for the proton but shows big discrepancies for the neutron.