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arXiv · 2310.17079

The Four-Boson First-Excited State Near Two-Body Unitarity

Feng Wu·T. Frederico·R. Higa·U. van Kolck
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Abstract

Near two-body unitarity, the three-boson system is characterized by an approximate discrete scale invariance manifest in a geometric tower of bound states (the Efimov effect). In the absence of a strong four-body force, the four-boson system has two states associated with each Efimov state, one very nearly unstable, the other several times deeper. We study correlations between the excited- and ground-state properties, such as binding energies and radii, up to next-to-leading order in an effective field theory for short-range forces. We obtain the parameters in these correlations from similar correlations arising from existing precise calculations based on short-range potentials. We also derive correlations among excited-state properties that emerge from the proximity of the state to the break-up threshold into a boson and a three-boson bound state, using an effective field theory for "halo" states.

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Feng Wu, T. Frederico, R. Higa, U. van Kolck. 2023-10-26. The Four-Boson First-Excited State Near Two-Body Unitarity. https://doi.org/10.1103/physreva.109.043301

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