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The Hypertriton in Effective Field Theory

H. -W. Hammer
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Abstract

Doublet Lambda d scattering and the hypertriton are studied in the framework of an effective field theory for large scattering lengths. As in the triton case, consistent renormalization requires a one-parameter three-body force at leading order whose renormalization group evolution is governed by a limit cycle. Constraining unknown parameters from symmetry considerations and the measured binding energy of the hypertriton, we calculate the low-energy phase shifts for doublet Lambda d scattering. For the low-energy parameters, we find a_{Lambda d}=(16.8^{+4.4}_{-2.4}) fm and r_{Lambda d}=(2.3 +/- 0.3) fm, where the errors are due to the uncertainty in the hypertriton binding energy. Since the hypertriton is extremely shallow, low-energy three-body observables in this channel are very insensitive to the exact values of the Lambda N low-energy parameters.

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H. -W. Hammer. 2001-10-18. The Hypertriton in Effective Field Theory. https://doi.org/10.1016/s0375-9474(02)00621-8

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