  Angle-resolved photoemission measurements on the electron-doped cuprate
Sm(1.85)Ce(0.15)CuO(4) evidence anisotropic dressing of charge-carriers due to
many-body interactions. Most significantly, the scattering rate along the zone
boundary saturates for binding energies larger than ~200 meV, while along the
diagonal direction it increases nearly linearly with the binding energy in the
energy range ~150-500 meV. These results indicate that many-body interactions
along the diagonal direction are strong down to the bottom of the band, while
along the zone-bounday they become very weak at energies above ~200 meV.
