Search for hidden orbital currents and observation of an activated ring of magnetic scattering in the heavy fermion superconductor URu2Si2

We have performed neutron-scattering experiments on the heavy fermion superconductor URu2Si2 to search for the orbital currents predicted to exist in the ordered phase below TN=17.5 K which result in a ring in momentum space. Elastic scans in the (H, K, 0) and (H, 0, L) planes revealed no such order parameter at low temperatures. This shows that any orbital current formation is quite small and less than our detection limit for a ring of …