Basis function calculations for the massive Schwinger model in the light-front Tamm-Dancoff approximation
Basis function calculations for the massive Schwinger model in the light-front Tamm-Dancoff approximation
复制标题
光锋 Tamm-Dancoff 近似中大规模 Schwinger 模型的基函数计算
DOI：
10.1006/jcph.1993.1171
复制
发表时间：
1993
影响因子：
4.1
通讯作者：
R. Perry
中科院分区：
文献类型：
--
作者：
Yizhang Mo;R. Perry
摘要利用光前场理论研究了大质量Schwinger模型。在对Fock空间作Tamm-Dancoff截断，使任何态都不允许超过四个粒子后，通过在有限基上展开两粒子和四粒子的振幅，求解电荷零态的耦合光波前Tamm-Dancoff积分方程，从而将原始方程转化为一个简单的矩阵方程。通过保留四粒子扇区，我们能够研究理论中能量最低的玻色子和第一激发态，对于无质量费米子来说，第一激发态是两个基态玻色子的散射态。对于无质量Schwinger模型的已知结果，用合理的小基得到了准确的再现，并且对现有的大质量模型的数值结果进行了复制和改进。本文利用Schwinger模型丰富的物理学知识，阐述了用基函数解哈密顿场论中的几个简单问题。
Abstract We use light-front field theory to study the massive Schwinger model. After making a Tamm-Dancoff truncation of Fock space so that no more than four particles are allowed in any state, the coupled light-front Tamm-Dancoff integral equations for charge zero states are solved by expanding the two-particle and four-particle amplitudes in a finite basis, thereby converting the original equations into a simple matrix equation. By retaining the four-particle sector we are able to study both the lowest energy boson of the theory and the first excited state, which for massless fermions is a scattering state of two ground state bosons. Known results for the massless Schwinger model are accurately reproduced with reasonably small bases, and existing numerical results for the massive model are reproduced and improved. The rich physics of the Schwinger model is used to elucidate several simple problems in the use of basis functions to solve Hamiltonian field theories.