Hidden-order pseudogap in URu2Si2

Through an analysis and modeling of data from various experimental techniques, we present clear evidence for the presence of a hidden-order pseudogap in URu2Si2 in the temperature range 25-17.5 K. Considering fluctuations of the hidden-order energy gap at the transition, we evaluate the effects that gap fluctuations would produce on observables like tunneling conductance, neutron scattering, and nuclear resonance, and relate them to the experimental findings. We show that the transition into the hidden-order phase is likely second order and is preceded by the onset of noncoherent hidden-order fluctuations.