  We study neutrino flavor evolution in the quantum many-body approach using
the full neutrino-neutrino Hamiltonian, including the usually neglected terms
that mediate non-forward scattering processes. Working in the occupation number
representation with plane waves as single-particle states, we explore the time
evolution of simple initial states with up to $N=10$ neutrinos. We discuss the
time evolution of the Loschmidt echo, one body flavor and kinetic observables,
and the one-body entanglement entropy. For the small systems considered, we
observe `thermalization' of both flavor and momentum degrees of freedom on
comparable time scales, with results converging towards expectation values
computed within a microcanonical ensemble. We also observe that the inclusion
of non-forward processes generates a faster flavor evolution compared to the
one induced by the truncated (forward) Hamiltonian.
