2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/82092The $^1 S_0$ pairing of symmetric nuclear matter is discussed in the frame work of relativistic nuclear theory with Dyson-Schwinger equations (DSEs). The in-medium nucleon and meson propagators are treated in a more self-consistent way through meson polarizations. The screening effects on mesons due to in-medium nucleon excitation are found to reduce the $^1S_0$ pairing gap and shift remarkably the gap peak to low density region.5 pages, identical to published version in PLB with typos correctedNuclear TheoryAstrophysicsStrongly Correlated ElectronsSuperconductivityHigh Energy Physics - Phenomenologytext