2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/215080We found that spin-one new light particle exchanges are strongly bounded by high-energy and small momentum transfer np elastic scattering data; the analogous bound for a scalar particle is considerably weaker, while for a pseudoscalar particle no bounds can be set. These bounds are compared with the bounds extracted from low-energy n-Pb scattering experiments and from the bounds of pi0 and K+ meson decays.16 pages with 4 figures; v2, v3 have minor grammatical changesHigh Energy Physics - Phenomenologytext