  Motivated by recent ultafast pump probe experiments on high-temperature
superconductors, we discuss the transient dynamics of a d-wave BCS model after
a quantum quench of the interaction parameter. We find that the existence of
gap nodes, with the associated nodal quasiparticles, introduces a dissipation
channel which makes the dynamics much faster than in the conventional s-wave
model. For every value of the quench parameters, the superconducting gap
rapidly converges to a stationary value smaller than the one at equilibrium.
Using a sudden approximation for the gap dynamics, we find an analytical
expression for the reduction of spectral weight close to the nodes, which is in
qualitative agreement with recent experiments.
