Loosely bound states of three particles

Abstract
The adiabatic hyperspherical technique is applied to a three-body system interacting via a short-range potential. Analytical expressions for the effective hyper-radial potential have been obtained without explicit use of the two-body potential. Possible loosely bound states of the system have been analyzed quantitatively and the result confirms the prediction by V. Efimov (Yad. Fiz. 10, 107 (1969) [Sov. J. Nucl. Phys. 10, 62 (1970)]). At the same time, some new characteristics of the three-body system are obtained.