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A renormalized equation for the three-body system with short-range interactions

H. -W. Hammer·Thomas Mehen
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Abstract

We study the three-body system with short-range interactions characterized by an unnaturally large two-body scattering length. We show that the off-shell scattering amplitude is cutoff independent up to power corrections. This allows us to derive an exact renormalization group equation for the three-body force. We also obtain a renormalized equation for the off-shell scattering amplitude. This equation is invariant under discrete scale transformations. The periodicity of the spectrum of bound states originally observed by Efimov is a consequence of this symmetry. The functional dependence of the three-body scattering length on the two-body scattering length can be obtained analytically using the asymptotic solution to the integral equation. An analogous formula for the three-body recombination coefficient is also obtained.

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H. -W. Hammer, Thomas Mehen. 2000-11-06. A renormalized equation for the three-body system with short-range interactions. https://doi.org/10.1016/s0375-9474(00)00710-7

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