Full-dimensional quantum mechanical study of three-body recombination for cold 4He-4He-20Ne system

The increase of the number of the two-body recombination channels strongly challenges the numerical calculation of the accurate rates for the three-body recombination (TBR) process and its reverse process, collision-induced dissociation (CID), at ultracold temperatures. By taking the He-4-He-4-Ne-20 collision system as an example, we have obtained the rates for its TBR and CID processes involving all four recombination channels, including the two-body states He-4(2) (l = 0) and (HeNe)-He-4-Ne-20 (l = 0, 1, 2) with l the rotational quantum number. By using the adiabatic hyperspherical method, we have considered not only total angular momentum J = 0 but also J > 0 in the ultracold collision energies (E = 0.01 - 100 mK x k(B)). It is found that He-4(2) (l = 0) is the major product after the TBR process in the ultracold limit (E = 0.1 mK x k(B)). The TBR rate into He-4(2) (l = 0) is nearly one order of magnitude larger than the sum of the other three products, (HeNe)-He-4-Ne-20 (l = 0, 1, 2). Moreover, the CID rates for the three (HeNe)-He-4-Ne-20 (l = 0, 1, 2) + He-4 initial states are close to each other and are smaller than that for the He-4(2) (l = 0) + Ne-20 initial state. Additionally, we have, for the first time, performed the channel-resolved scattering calculation that can explain the above-mentioned findings quantitatively.

Automated summary

By studying the He-4-He-4-Ne-20 collision system, the researchers have calculated the rates for the three-body recombination and collision-induced dissociation processes. It was found that He-4(2) (l = 0) is the dominant product of recombination at ultracold temperatures, with a rate significantly higher than the other three products.