The weakly bound states and resonances of the BeHe2 triatomic system

In the present study, we carry out a full search of the bound states and resonances of the He2Be triatomic system, with its isotopic variants (He2Be)-He-3-Be-9, (HeHeBe)-He-3-He-4-Be-9, and (He2Be)-He-4-Be-9 using the hyperspherical method. Three-body long-range effects are also included in the computation by adding to the additive potential the Axilrod-Teller triple-dipole term. In addition, the possibility of the occurrence of Efimov-type states in these systems is discussed. We have found a bound state for each of the (He2Be)-He-3-Be-9 and (HeHeBe)-He-3-He-4-Be-9 trimers, while one weakly bound excited state is also found to exist for the (He2Be)-He-4-Be-9 system. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3587243]