ADIABATIC HYPERSPHERICAL STUDY OF THE HELIUM TRIMER

The adiabatic hyperspherical method is used to investigate the spectru m of the helium trimer and to explore effects on the spectrum of varyi ng the helium masses as well as the interaction strength. When a reali stic helium dimer potential is adopted, only two isotopic combinations are observed to have three-body bound states: He-4(3) and He-4(2) He- 3. By artificially adjusting the dimer potential, we also determine th e range of interaction strengths for which halo states can result. The existence of Efimov states for both physical and unphysical systems i s also examined.