Top: maximum of the mode intensity fluctuation (δL/L)_max as a function of L/M. The filled circles correspond to the seismic measurements performed by Baudin et al. (2011) on a large number of CoRoT red giant stars (~170 targets). We only considered the targets for which the mode line width is broader than twice the frequency resolution (see Sect. 3.1). The empty circles correspond to the MS stars observed so far by CoRoT (see Baudin et al. 2011), and the blue squares are the theoretical (δL/L)_max computed according to the Kjeldsen & Bedding (1995) adiabatic coefficient (Eq. (16), see Sect. 3.3.1). The red square corresponds to the median value of the theoretical and the associated vertical bar corresponds to the bias introduced by the 1-σ error associated with the parameters p _∗ , s, , and ℳ_0, ∗ , and (see Eq. (15)). Bottom: same as top, the theoretical (δL/L)_max are computed here assuming for ζ the non-adiabatic scaling relation established in Sect. 2.4.2 (see also Fig. 2). The red error bar here also accounts for the 1-σ error associated with the parameters k and ζ₀ (see Eq. (17) and Sect. 2.4.2).