标题： 一阶变分法在标量核子-介子理论中的形式因子计算 显示英文标题

标题： First Order Variational Calculation of Form Factor in a Scalar Nucleon--Meson Theory

摘要： 我们使用非微扰变分技术在粒子表示中研究了一种相对论量子场论。 该理论涉及两种质量标量粒子，即“核子”和“介子”，通过杨-米尔斯耦合相互作用。 我们在核子的冻结近似下计算了涉及两个外部核子和任意数量外部介子的一般欧几里得格林函数。 非微扰重整化和截断以一致的方式进行，并导致与外部介子数量无关的相同变分泛函。 我们验证了该计算对于小耦合与一环微扰理论一致。 作为说明，详细考虑了介子在核子上的吸收这一特殊情况。 我们推导了裸粒子的半径，并在解析延拓到闵可夫斯基空间后数值研究了顶点函数。 显示英文摘要

摘要： We investigate a relativistic quantum field theory in the particle representation using a non-perturbative variational technique. The theory is that of two massive scalar particles, `nucleons' and `mesons', interacting via a Yukawa coupling. We calculate the general Euclidean Green function involving two external nucleons and an arbitrary number of external mesons in the quenched approximation for the nucleons. The non-perturbative renormalization and truncation is done in a consistent manner and results in the same variational functional independent of the number of external mesons. We check that the calculation agrees with one-loop perturbation theory for small couplings. As an illustration the special case of meson absorption on the nucleon is considered in detail. We derive the radius of the dressed particle and numerically investigate the vertex function after analytic continuation to Minkowski space.