标题： 二环形式因子在QED中 显示英文标题

标题： Two-Loop Form Factors in QED

摘要： 我们通过积分相应的色散关系来评估电子在任意动量转移和有限电子质量下的壳上形式因子，在QED中计算到两环，这些色散关系涉及早已知的虚部。 红外发散性用一个虚构的小光子质量来参数化。 结果以最大权重为4的调和多对数形式表示。 还给出了小动量转移和大动量转移的展开式。 显示英文摘要

摘要： We evaluate the on shell form factors of the electron for arbitrary momentum transfer and finite electron mass, at two loops in QED, by integrating the corresponding dispersion relations, which involve the imaginary parts known since a long time. The infrared divergences are parameterized in terms of a fictitious small photon mass. The result is expressed in terms of Harmonic Polylogarithms of maximum weight 4. The expansions for small and large momentum transfer are also given