  We report on combined neutron and resonant x-ray scattering results,
identifying the nature of the spin-orbital ground state and magnetic
excitations in LuVO3 as driven by the orbital parameter. In particular, we
distinguish between models based on orbital Peierls dimerization, taken as a
signature of quantum effects in orbitals, and Jahn-Teller distortions, in favor
of the latter. In order to solve this long-standing puzzle, polarized neutron
beams were employed as a prerequisite in order to solve details of the magnetic
structure, which allowed quantitative intensity-analysis of extended magnetic
excitation data sets. The results of this detailed study enabled us to draw
definite conclusions about classical vs quantum behavior of orbitals in this
system and to discard the previous claims about quantum effects dominating the
orbital physics of LuVO3 and similar systems.
