  We reveal a significant spin-exchange pathway in the three-body recombination
process for ultracold lithium-7 atoms near a zero-crossing of the two-body
scattering length. This newly discovered recombination pathway involves the
exchange of spin between all three atoms, which is not included in many
theoretical approaches with restricted spin structure. Taking it into account,
our calculation is in excellent agreement with experimental observations. To
contrast our findings, we predict the recombination rate around a different
zero-crossing without strong spin-exchange effects to be two orders of
magnitude smaller, which gives a clear advantage to future many-body
experiments in this regime. This work opens new avenues to study elementary
reaction processes governed by the spin degree of freedom in ultracold gases.
