Anomalous normal state electronic Raman scattering continuum in YBCO: Inadequacy of frequency-dependent collision-rate models

We calculate the intraband electronic Raman scattering cross section from charge density fluctuations of holes in YBCO and the real part of the transverse electromagnetic conductivity in the normal state, using phenomenological linear frequency-dependent collision rates ω c(ω, T). Whereas there is a general agreement with the experimental data on infrared conductivity, we are unable to obtain the extent of flatness of the electronic Raman continuum as observed in several experiments.