A Study of the Set of All Physically Equivalent Configurations of a Single Feynman Diagram in a String Theory with a Compactified Dimension

We consider a one loop Feynman diagram in a string theory in which one dimension has been compactified and thus some of the variables running in the loop are always discrete. Considering one particular Feynman diagram, we claim that the set of all physically equivalent (meaning they have the same value of the external parameters, like momentum and winding number) configurations of this diagram can be given a group structure and the group is a very well known cyclic group.