  We study the contribution of the electron-spin fluctuation coupling to the
superconducting state of the two dimensional Hubbard model within dynamical
cluster approximation (DCA) using a numerical exact continuous time Monte Carlo
solver. By analyzing the frequency dependence of the self energy, we show that
only about half of the superconductivity can be attributed to a "pairing glue"
arising from treating spin fluctuations as a pairing boson in the standard
one-loop theory.
