Cooper pair formation in U(1) gauge theory of high temperature superconductivity

We study the two-dimensional spin-charge separated Ginzburg-Landau (GL) the ory containing U(1) gauge interactions as a semi-phenomenological model des cribing fluctuating condensates in high temperature superconductivity. Base d on the original GL action, we derive the effective action of Cooper pair. Especially, we clarify how Cooper pair correlation evolves in the normal s tate from the point of view of spin-charge separation. Furthermore, we show how Cooper pair couples to gauge field in a gauge-invariant way stressing the insensitivity of Cooper pair to infrared gauge field fluctuation.