Binding energies of light, A≤6, ΛΛ hypernuclei are calculated using the stochastic variational method in a pionless effective field theory (π̸EFT) approach at leading order with the purpose of assessing critically the onset of binding in the strangeness S=−2 hadronic sector. The π̸EFT input in this sector consists of (i) a ΛΛ contact term constrained by the ΛΛ scattering length aΛΛ, using a range of values compatible with ΛΛ correlations observed in relativistic heavy ion collisions, and (ii) a ΛΛN contact term constrained by the only available A≤6 ΛΛ hypernucler binding energy datum of ΛΛ 6He. The recently debated neutral three-body and four-body systems ΛΛ 3n and ΛΛ 4n are found unbound by a wide margin. A relatively large value of |aΛΛ|≳1.5 fm is needed to bind ΛΛ 4H, thereby questioning its particle stability. In contrast, the particle stability of the A=5 ΛΛ hypernuclear isodoublet ΛΛ 5H–ΛΛ 5He is robust, with Λ separation energy of order 1 MeV.
|Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
|Published - 10 Oct 2019
Bibliographical notePublisher Copyright:
© 2019 The Author(s)
- LO π̸EFT
- Light ΛΛ hypernuclei
- SVM calculations