2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/209673We report neutron scattering measurements of cooperative spin excitations in antiferromagnetically ordered BaFe2As2, the parent phase of an iron pnictide superconductor. The data extend up to ~100meV and show that the spin excitation spectrum is sharp and highly dispersive. By fitting the spectrum to a linear spin-wave model we estimate the magnon bandwidth to be in the region of 0.17eV. The large characteristic spin fluctuation energy suggests that magnetism could play a role in the formation of the superconducting state.4 pages, 4 figures; v2: minor changes to the text and abstract and more general expressions for the linear spin-wave cross section includedSuperconductivityStrongly Correlated Electronstext