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arXiv · 1905.05117

$d$-dimensional L\"uscher's formula and the near-threshold three-body states in a finite volume

Shangguo Zhu·Shina Tan
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Abstract

We study two particles colliding in a $d$-dimensional finite volume and generalize L\"uscher's formula to arbitrary $d$ spatial dimensions. We obtain the $s$- and $p$-wave approximations of the generalized L\"uscher's formula. For resonant $s$- or $p$-wave interactions, we analytically determine the energies of the low-lying states at large box size $L$. At $s$-wave resonance, we discover two low-lying states with nearly opposite energies, which are proportional to $\pm 1/L^{d/2}$ for $d\ge 5$, or $\pm 1/L^{2}\sqrt{\ln L}$ for $d=4$. This provides important insights into the near-threshold states of three bosons at a three-body resonance in a 2- or higher-dimensional finite volume.

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Shangguo Zhu, Shina Tan. 2019-05-13. $d$-dimensional L\"uscher's formula and the near-threshold three-body states in a finite volume. https://arxiv.org/abs/1905.05117

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