标题： 强磁场中的中子：有限体积效应 显示英文标题

标题： Neutron in a Strong Magnetic Field: Finite Volume Effects

摘要： 我们借助手征微扰理论研究了中子在环面在磁场中的响应，并揭示了非零全纯量带来的效应。 确定这些效应需要对磁场进行非微扰处理；为此，我们采用了强场幂次计数方法。 通过一种新颖的坐标空间方法，我们发现中子在一个由积分绕环面缠绕的带电π介子消去后得到的有效势中传播，而该有效势是坐标依赖的。 了解这些有限体积效应将有助于从外部磁场下的格点QCD计算中提取中子性质。 特别是，我们得到了中子磁矩和磁极化率的有限体积修正。这些量在文献中尚未被正确计算。 除了非零全纯量带来的效应外，有限体积修正还取决于通过阿哈罗诺夫-玻姆效应的磁通量子。 我们做出了一些观察，展示了目前格点QCD计算中所用强磁场的非微扰效应的重要性。这些观察涉及有限体积和无限体积下的中子物理。 显示英文摘要

摘要： We investigate the neutron's response to magnetic fields on a torus with the aid of chiral perturbation theory, and expose effects from non-vanishing holonomies. The determination of such effects necessitates non-perturbative treatment of the magnetic field; and, to this end, a strong-field power counting is employed. Using a novel coordinate-space method, we find the neutron propagates in a coordinate-dependent effective potential that we obtain by integrating out charged pions winding around the torus. Knowledge of these finite volume effects will aid in the extraction of neutron properties from lattice QCD computations in external magnetic fields. In particular, we obtain finite volume corrections to the neutron magnetic moment and magnetic polarizability. These quantities have not been computed correctly in the literature. In addition to effects from non-vanishing holonomies, finite volume corrections depend on the magnetic flux quantum through an Aharonov-Bohm effect. We make a number of observations that demonstrate the importance of non-perturbative effects from strong magnetic fields currently employed in lattice QCD calculations. These observations concern neutron physics in both finite and infinite volume.