Wilson Line Integrals in the Unparticle Action

Understand

We consider the unparticle action that is made gauge invariant by inclusion of an open Wilson line factor.

• In deriving vertexes from such an action it has been customary to use a form of differentiating the Wilson line originally proposed by Mandelstam.
• Using a simple example, we show that the Mandelstam derivative is mathematically inconsistent.
• We show that there are two ways to define differentiation of the Wilson line.