标题： 利用低能康普顿散射约束非壳上效应 显示英文标题

标题： Constraining off-shell effects using low-energy Compton scattering

摘要： 带外效应在质子电磁顶点中的影响可以从它们对已知过程的影响中得到约束。 特别是，用于描述带外效应的模型参数可以通过拟合低能康普顿散射中测量的质子电极化率和磁极化率来确定。 最近有推测认为，带外效应为μ子氢的兰姆位移提供了足够的能量，足以解释μ子和电子测量的质子半径之间的差异。 我们发现，这里讨论的约束使得带外效应比为此目的所需的量小两个数量级。 显示英文摘要

摘要： Off-shell effects in proton electromagnetic vertices can be constrained from their effects on known processes. In particular, parameters in models for the off-shell effects can be determined by fitting to the proton electric and magnetic polarizabilities measured in low-energy Compton scattering. There has been recent speculation that off-shell effects contribute enough energy to the muonic hydrogen Lamb shift to explain the discrepancy between muonic and electronic measurements of the proton radius. We find that the constraints discussed here make the off-shell effects about two orders of magnitude smaller than needed for this purpose.