  Four-boson Efimov physics is well known in the negative energy regime but far
less above the four-body breakup threshold. The part of this region with
negative two-boson scattering length is studied solving rigorous four-particle
scattering equations for transition operators in the momentum space. Moving
away from the unitary limit the Efimov tetramers evolve from unstable bound
states into resonances. Their energies and widths are studied as functions of
the two-boson scattering length; a universal behavior is established and given
in a dimensionless representation. The Efimov tetramers have finite width in
the whole regime; they broaden rapidly in the resonance regime but remain
narrower than the associated trimer. The resonant behavior is most clearly seen
in the four-particle recombination rate.
