Contribution to the quasiparticle inelastic lifetime from paramagnons in disordered superconductors

The paramagnon contribution to the quasiparticle inelastic-scattering rate in disordered superconductors is presented. Using Anderson's exact eigensta te formalism, it is shown that the scattering rate is Stoner enhanced and i s further enhanced by the disorder relative to the clean case in a manner s imilar to the disorder enhancement of the long-range Coulomb contribution.- The results are discussed in connection with the possibility of conventiona l or unconventional superconductivity in the borocarbides. The results are compared to recent tunneling experiments on LuNi2B2C.