Nodal Quasiparticle Lifetime in the Superconducting State of BSCCO(2212)

We have measured the complex conductivity of a BSCCO(2212) thin film between 0.2 and 1.0 THz. We find the conductivity in the superconducting state to be well described as the sum of contributions from quasiparticles, the condensate, and order parameter fluctuations which draw 30% of the spectral weight from the condensate. An analysis based on this decomposition yields a quasiparticle scattering rate on the order of k_(B)*T/(hbar) for temperatures below Tc.