Finite quasiparticle lifetime in disordered superconductors
  We investigate the complex conductivity of a highly disordered MoC superconducting film with $k_Fl\approx 1$, where $k_F$ is the Fermi wavenumber and $l$ is the mean free path, derived from experimental transmission characteristics of coplanar waveguide resonators in a wide temperature range below the superconducting transition temperature $T_c$. We find that the original Mattis-Bardeen model with a finite quasiparticle lifetime, $\tau$, offers a perfect description of the experimentally observed complex conductivity. We show that $\tau$ is appreciably reduced by scattering effects. Characteristics of the scattering centers are independently found by the scanning tunneling spectroscopy and agree with those determined from the complex conductivity. 
M. \v{Z}emli\v{c}ka, P. Neilinger, M. Trgala, D.Manca, M. Grajcar, P.   Szabo, P. Samuely, \v{S}. Ga\v{z}i, U. H\"ubner, V. ...
cond-mat.supr-con