TY - JOUR
T1 - The onset of ΛΛ hypernuclear binding
AU - Contessi, L.
AU - Schäfer, M.
AU - Barnea, N.
AU - Gal, A.
AU - Mareš, J.
N1 - Publisher Copyright:
© 2019 The Author(s)
PY - 2019/10/10
Y1 - 2019/10/10
N2 - 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.
AB - 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.
KW - LO π̸EFT
KW - Light ΛΛ hypernuclei
KW - SVM calculations
UR - http://www.scopus.com/inward/record.url?scp=85071555018&partnerID=8YFLogxK
U2 - 10.1016/j.physletb.2019.134893
DO - 10.1016/j.physletb.2019.134893
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AN - SCOPUS:85071555018
SN - 0370-2693
VL - 797
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
M1 - 134893
ER -