Same as Fig. 10, but for models with different initial masses, as indicated in the legend. We show only the region around the stable core-helium burning phase. All models have an additional viscosity of ν_add = 5 × 10⁵ cm² s⁻¹. The data points correspond to red clump stars from Mosser et al. (2012). Dotted lines: before stable core-helium burning. Solid lines: long and stable core-helium burning phase (see text). Dash-dotted lines: last fraction of the stable core-helium burning phase.