Cold atom-atom-ion three-body recombination of 4 He- 4 He-X - (X = H or D).

The atom-atom-ion three-body recombination (TBR) of mixed4 He and X- (X = H or D) systems is investigated by solving the Schrödinger equation using the adiabatic hyperspherical representation method. It is shown that the dominant products after a TBR in the ultracold limit (E ≤ 0.1 mK × kB ) are different for the two systems. For the4 He4 HeH- system, the rate of TBR into the4 HeH- ion is nearly two orders of magnitude larger than that of TBR into the neutral4 He2 molecule. In contrast, the yield of4 He2 is a little higher than that of4 HeD- for the4 He4 HeD- system. Furthermore, since the adiabatic potentials become more attractive and the nonadiabatic couplings become much stronger by substituting D for H in the4 He4 HeH- system, the total TBR rate for the4 He4 HeD- system is nearly two orders of magnitude larger than that for the4 He4 HeH- system.