Studying the Validity of the Quasi-Classical Approach to Three-Body Decays

The hyperspherical harmonics approach is especially suited to studies of true three-body decays. Reducing the hyperspherical equations set to a single-channel approximation provides the basis for using the standard quasi-classical expression for calculating resonance widths. It is shown that the quasi-classical approach is itself quite precise when applied to the three-body single-channel effective potentials. However, reduction to the single-channel formalism seems to be unacceptable, as it leads to considerable overestimation of decay widths.