Dear Sir. Concerning your issue about the determination of pairing energy experimentally. the quantitative determination of the normal and pairing self-energies, made possible by laser-based angle-resolved photoemission measurements with unprecedented accuracy and stability. Through a precise inversion procedure, both the effective interactions in the attractive d-wave symmetry and the repulsive part in the full symmetry are determined. The latter are nearly angle independent. Near Tc both interactions are nearly independent of frequency, and have almost the same magnitude, over the complete energy range of up to about 0.4 eV except for a low energy feature around 50 meV present only in the repulsive part which has less than 10% of the total spectral weight. Well below Tc, they both change similarly by superconductivity induced features at low energies. Besides finding the pairing self-energy and the attractive interactions for the first time, these results expose a central paradox of the high Tc problem: how the same frequency independent fluctuations can dominantly scatter at angles ± bi /2 in the attractive channel as well as lead to angle-independent repulsive scattering. The experimental results are compared with the available theoretical calculations based on antiferromagnetic fluctuations, Hubbard model and the quantum-critical fluctuations of loop-current order. I think the following below links may help you in your analysis: