  Three-boson Efimov physics is well known in the bound-state regime, but far
less in the three-particle continuum at negative two-particle scattering length
where Efimov states evolve into resonances. They are studied solving rigorous
three-particle scattering equations for transition operators in the momentum
space. The dependence of the three-boson resonance energy and width on the
two-boson scattering length is studied with several force models. The universal
limit is determined numerically considering highly excited states; simple
parametrizations for the resonance energy and width in terms of the scattering
length are established. Decreasing the attraction, the resonances rise not much
above the threshold but broaden rapidly and become physically unobservable,
evolving into subthreshold resonances. Finite-range effects are studied and
related to those in the bound-state regime.
