2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/180386Positivity constraints are derived on pion-nucleon scattering amplitudes and their even-order derivatives inside the Mandelstam Triangle with the help of dispersion relations. Fairly interesting constraints are obtained on some of the low energy constants, by a combination of the chiral perturbation theory for heavy baryons and existing fitting results from available pion-nucleon phase shifts at intermediate energies.version to appear in Phys. Lett. B. 6 pagesHigh Energy Physics - PhenomenologyHigh Energy Physics - TheoryNuclear Theorytext