2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/82271The np pair in the spin-singlet state is treated as a Cooper np-pair within the extension of the Nambu-Jona-Lasinio model of light nuclei, describing the deuteron as a Cooper np-pair in the spin-triplet state. For the Cooper np-pair in the spin-singlet state we compute the binding energy and express the S-wave scattering length of np scattering in the spin-singlet state in terms of the binding energy. The theoretical value of the S-wave scattering length of np scattering agrees well with the experimental data.4 page, no figures, LatexNuclear TheoryAstrophysicsSuperconductivityHigh Energy Physics - Phenomenologytext