Same as Fig. 13 for ¹²C/¹³C as a function of stellar mass. In the right panel, the mass loss rate is decreased on the RGB by a factor of two compared to the left and right panels (see text for details). The stellar age is colour-coded for both observations and BGM simulations. The green lines in the middle panel show the ¹²C/¹³C at the core He-burning phase predicted by stellar evolution models computed by Lagarde et al. (2012a) and including both thermohaline and rotation-induced mixing (at V/V_crit ∼ 0.3) at [Fe/H] = 0 and [Fe/H] = −0.86 (dotted and dashed line, respectively).