Values of the parameter ${\stackrel{\sim }{\chi }}^2(s_{12},s_{13})$ defined in Eq. (11) for the single-scale connected 3PCF obtained for M_ν = 0.4 eV. Each panel corresponds to a different redshift. From left to right, z = 0, 1, and 2. The lines overplotted on the left panel are taken as representative of regions with a stronger signal, and they identify isosceles triangles (dashed black line with η = 0, where the signal is only enhanced on scales ≲30 h⁻¹ Mpc), quasi-isosceles triangles with η = 4 (dashed green line), and triangles with s₁₂ = 10 h⁻¹ Mpc (dash-dotted blue line). The numbered circles on the lines identify some (s₁₂, s₁₃) configurations that correspond in increasing order from 1 to 4 to (10,100), (30,100), (55,100), and (30,50) h⁻¹ Mpc. For them, we plot the single-scale ζ in Fig. 2.