2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/179311We calculate the forward spin-dependent photon-nucleon Compton amplitudes $S_1$ and $S_2$ as functions of photon energy $ν$ and mass $Q^2$ at the next-to-leading (${\cal O}(p^4)$) order in chiral perturbation theory, from which we extract the contribution to a generalized Drell-Hearn-Gerasimov sum rule at low $Q^2$. The result indicates a much rapid $Q^2$ variation of the sum rule than a simple dimensional analysis would yield.7 pages, latex, one figure includedHigh Energy Physics - Phenomenologytext