双光子交换对弹性e + p --> e + p过程的贡献
Two Photon Exchange Contributions to Elastic e + p --> e + p Process in a Nonlocal Field Formalism
摘要：
计算了双光子交换对极化电子与靶质子弹性散射的贡献。我们使用非局部场论形式主义的计算。形式主义保持规范不变性，并提供了一个系统的程序，使这种计算。结果取决于一个未知参数\bar b。我们计算了双光子交换修正的比例的电，磁形状因子提取使用偏振传输实验。如果\bar b ~ 1，则发现校正很小。然而，对于\bar b>3的较大值，校正可能相当显著。对偏振传输结果的修正方向正确，解释了其与Rosenbluth分离法测量值的差异。我们发现，两个实验结果之间的差异可以解释为参数\bar b的值范围很广。我们还发现，由于双光子交换引起的修正依赖于光子的纵向偏振态。因此，我们预测使用偏振转移技术提取的形状因子比的偏振依赖性。最后，我们得到了一个限制\bar b的要求，非极化的约化截面的非线性依赖于λ在实验误差范围内。
英文摘要：
We compute the two photon exchange contributions to elastic scattering of polarized electrons from target protons. We use a nonlocal field theory formalism for this calculation. The formalism maintains gauge invariance and provides a systematic procedure for making this calculation. The results depend on one unknown parameter \bar b. We compute the two photon exchange correction to the ratio of electric to magnetic form factors extracted using the polarization transfer experiments. The correction is found to be small if \bar b ~ 1. However for larger values of \bar b>3, the correction can be quite significant. The correction to the polarization transfer results goes in the right direction to explain their difference with the ratio measured by Rosenbluth separation method. We find that the difference between the two experimental results can be explained for a wide range of values of the parameter \bar b. We also find that the corrections due to two photon exchange depend on the photon longitudinal polarization epsilon. Hence we predict an epsilon dependence of the form factor ratio extracted using the polarization transfer technique. Finally we obtain a limit on \bar b by requiring that the non-linearity in epsilon dependence of the unpolarized reduced cross section is within experimental errors.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
