Abstract

" We have calibrated the linewidth/K vs. mass ratio relation for SU UMa stars using the ""superhump"" mass ratio derived from the tidal resonance model. We find that the relation by Jurcevic et al. (1994) is valid for dwarf novae above the period gap but not for SU UMa stars. Under the hypothesis of Keplerian disks, our results are compatible with the removal of the inner disk in SU UMa stars with extreme cycle lengths. The large long-term FW H M variability observed in WZ Sge suggests that the fraction of mass removed from the disk is variable and possibly a function of the supercycle phase. We show a new empirical formula between mass ratio and FW H M/K. It fits the mass ratio of dwarf novae above and below the period gap with a mean relative dispersion of 16% and 26%, respectively, except for the post-period minimum candidates EG Cnc and WZ Sge. "