The hypertriton in effective field theory

Abstract

Doublet Λd 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 oneparameter 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 Λd scattering. For the low-energy parameters, we find a Λd = (16.8 +4.4 −2.4 ) fm and r Λd = (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 ΛN low-energy parameters.

Hyperon–nucleon interactions—a chiral effective field theory approach

“…These authors used a chiral interaction containing four-baryon contact terms and pseudoscalar-meson exchanges. Recently, the hypertriton and Λd scattering were investigated in the framework of an EFT with contact interactions [9]. Korpa et al [10] performed a next-to-leading order (NLO) EFT analysis of Y N scattering and hyperon mass shifts in nuclear matter.…”

Hadronic Interactions From Lattice QCD

“…[174,175], for example, six different models are constructed, each describing the available YN cross-section data equally well, but predicting different values for the phase shifts. The effective field theory approach [179,180,181,182,183] is less developed and suffers from a large number of couplings that need to be fit to the data.…”

Few-Body Universality in Halo Nuclei

“…[39]. Finally, halo nuclei containing strange baryons are also amenable to halo EFT [40][41][42][43], but the scarcity of data in this sector presents a particular challenge.…”