O(3)非线性σ模型中拓扑项的可移性问题

Removability of the Topological Term in the O(3) Nonlinear σ-model

O(3)非线性σ模型的经典理论中的拓扑项可以用一适当的正则变换移去。本文研究了该模型的量子理论,求出了上述正则变换相应的量子么正变换,并讨论了此么正变换的意义及拓扑项的可移性问题。

It is shown that the topological term in the O(3) nonlinear σ-model can be removed by a suitable canonical transformation in the classical theory of the model. In this paper, the quantum unitary transformation corresponding to the classical canonical transformation is found. The meaning of the unitary transformation and the removability of the topological term are then discussed.