Fit of the oscillation pattern of the RGB star KIC 6144777, showing the pressure radial orders n_p from 9 to 12. The power spectrum density has been divided by the fit of the background. Radial and quadrupole modes are highlighted in red and green. The expected locations of dipole mixed modes are labelled with their mixed radial orders. When detected, mixed modes are highlighted in dark blue (m = −1), light blue (m = 0), or purple (m = 1). ℓ = 3 modes, which are also mixed, are located near the abscissa 0.22; extra peaks in the range [−0.2, −0.05] are mixed quadrupole modes. The gray dashed lines indicate the two thresholds used in this work, corresponding to height-to-background ratios of 7 and 10.