Theory of high-energy features in single-particle spectra of hole-doped cuprates

The recent angle-resolved photoemission measurements performed up to binding energies of the order of 1 eV reveal a very robust feature: The nodal quasiparticle dispersion breaks up around 0.3-0.4 eV and reappears around 0.6-0.8 eV. The intensity map in the energy-momentum space shows a waterfall-like feature between these two energy scales. We demonstrated that these experimental features may follow naturally from the strong correlation effects built in the familiar t-J model, and the waterfall reflects the fact that the low energy quasiparticles are pulled out of the soft lower Hubbard band at higher binding energies.