标题： 量子场论中散射振幅与Bethe-Salpeter波函数之间的关系 显示英文标题

标题： Relation between scattering amplitude and Bethe-Salpeter wave function in quantum field theory

摘要： 我们讨论量子场论中两个粒子散射振幅与贝茨-萨尔皮特（BS）波函数在相互作用范围内的精确关系。 在这个关系中，由BS波函数定义的约化BS波函数起着关键作用。 通过这个关系可以计算出壳和半离壳振幅。 我们还表明，使用从BS波函数确定的有效势求解薛定谔方程，仅在确定有效势的动量处给出正确的出壳散射振幅。 此外，我们讨论了约化BS波函数的导数展开以及在时间依赖的HALQCD方法中获得与插值算符无关结果的条件。 显示英文摘要

摘要： We discuss an exact relation between the two-particle scattering amplitude and the Bethe-Salpeter (BS) wave function inside the interaction range in quantum field theory. In the relation the reduced BS wave function defined by the BS wave function plays an essential role. Through the relation the on-shell and half off-shell amplitudes can be calculated. We also show that the solution of Schr\"odinger equation with the effective potential determined from the BS wave function gives a correct on-shell scattering amplitude only at the momentum where the effective potential is determined. Furthermore we discuss a derivative expansion of the reduced BS wave function and a condition to obtain results independent of the interpolating operators in the time-dependent HALQCD method.