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arXiv · 1506.04949

Four-boson bound states from a functional renormalisation group

Benjamin Jaramillo Avila·Michael C. Birse
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Abstract

We use the functional renormalisation group to study the spectrum of three- and four-body states in bosonic systems around the unitary limit. Our effective action includes all energy-independent contact interactions in the four-atom sector and we introduce a running trimer field to eliminate couplings that involve the atom-atom-dimer channel. The results show qualitatively similar behaviour to those from exact approaches. The truncated action we use leads to overbinding of the two four-body states seen in those treatments. It also generates a third state, although only for a very narrow range of two-body scattering lengths.

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Benjamin Jaramillo Avila, Michael C. Birse. 2015-06-16. Four-boson bound states from a functional renormalisation group. https://doi.org/10.1103/physreva.92.023601

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