English

Recombination in the universal four-fermion system

Quantum Gases 2021-09-02 v2 Nuclear Theory Atomic Physics

Abstract

In the systems of spin 12\frac12 fermions with resonant SS-wave interactions supporting only weakly bound dimers the antisymmetry forbids recombination of three (or more) fermions at zero energy. However, the fermion-fermion-dimer recombination is only partially suppressed. It is studied in the framework of momentum-space integral equations for the four-particle transition operators. In the vicinity of the unitary limit the fermion-fermion-dimer recombination rate, rescaled to build dimensionless quantity, is found to be linear in the effective range parameter, enabling a simple and accurate parametrization as well as evaluation of finite-range effects for any potential model. This feature makes the present results very useful in benchmarking different methods for three-cluster breakup and recombination calculations in four-particle systems. The interplay of the three-fermion and fermion-fermion-dimer recombination processes and their consequences for ultracold mixtures of fermions and dimers is discussed.

Keywords

Cite

@article{arxiv.2105.09033,
  title  = {Recombination in the universal four-fermion system},
  author = {A. Deltuva},
  journal= {arXiv preprint arXiv:2105.09033},
  year   = {2021}
}

Comments

modified definition of the recombination rate

R2 v1 2026-06-24T02:15:22.397Z