Abstract
We report a neutron scattering study of the magnetic excitation spectrum in each of the three temperature and pressure driven phases of URu2Si2. We find qualitatively similar excitations throughout the (H0L) scattering plane in the hidden order and large moment phases, with no changes in the hbar-omega-widths of the excitations at the Sigma = (1.407,0,0) and Z = (1,0,0) points, within our experimental resolution. There is, however, an increase in the gap at the Sigma point and an increase in the first moment of both excitations. At 8 meV where the Q-dependence of
magnetic scattering in the hidden order phase is extended in Q-space, the excitations in the large moment phase are sharper. The expanded Q-hbar-omega coverage of this study suggest more complete nesting within the antiferromagnetic phase, an important property for future theoretical
predictions of a hidden order parameter.
