Scattering and resonances in the ⁴He three-atomic system

A mechanism of disappearance and formation of the Efimov levels of the helium ^4He_3 trimer is studied when the force of interatomic interaction is changed. The resonances including virtual levels are calculated by the method based on the solving the boundary value problem, at complex energies, for the Faddeev differential equations describing the (2+1 --> 2+1; 1+1+1) scattering processes.