2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/191672We explore production mechanism and final state interaction in the $pp \to nK^ + Σ^ +$ channel based on the inconsistent experimental data published respectively by COSY-11 and COSY-ANKE. The scattering parameter $a> 0$ for $nΣ^ +$ interaction is favored by large near-threshold cross section within a nonrelativistic parametrization investigation, and a strong $nΣ^ +$ interaction comparable to $pp$ interaction is also indicated. Based on this analysis we calculate the contribution from resonance $Δ^* (1920)$ through $π^ +$ exchange within resonance model, and the numerical result suggests a rather small near-threshold total cross section, which is consistent with the COSY-ANKE data. With an additional sub-threshold resonance $Δ^*(1620)$, the model gives a much better description to the rather large near-threshold total cross section published by COSY-11.10pp + 4figs, published versionNuclear Theorytext