The onset of Lambda Lambda hypernuclear binding

0509906 - ÚJF 2020 RIV NL eng J - Journal Article
Contessi, L. - Schäfer, Martin - Barnea, N. - Gal, A. - Mareš, Jiří
The onset of Lambda Lambda hypernuclear binding.
Physics Letters. B. Roč. 797, č. 10 (2019), č. článku 134893. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA ČR GA19-19640S
Institutional support: RVO:61389005
Keywords : Light Lambda Lambda hypernuclei * LO (sic) pEFT * SVM calculations
OECD category: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Impact factor: 4.384, year: 2019
Method of publishing: Open access
https://doi.org/10.1016/j.physletb.2019.134893

Binding energies of light, A <= 6, Lambda Lambda hypernuclei are calculated using the stochastic variational method in a pionless effective field theory ((sic)pEFT) approach at leading order with the purpose of assessing critically the onset of binding in the strangeness S = -2 hadronic sector. The (sic)EFT input in this sector consists of (i) a Lambda Lambda contact term constrained by the Lambda Lambda scattering length a(Lambda Lambda), using a range of values compatible with Lambda Lambda correlations observed in relativistic heavy ion collisions, and (ii) a Lambda Lambda N contact term constrained by the only available A <= 6 Lambda Lambda hypernucler binding energy datum of He-6(Lambda Lambda). The recently debated neutral three-body and four-body systems (3)(Lambda Lambda)n and (4)(Lambda Lambda)n are found unbound by a wide margin. A relatively large value of vertical bar a(Lambda Lambda)vertical bar greater than or similar to 1.5 fm is needed to bind H-4(Lambda Lambda), thereby questioning its particle stability. In contrast, the particle stability of the A = 5 Lambda Lambda hypernuclear isodoublet H-5(Lambda Lambda)-He-5(Lambda Lambda) is robust, with Lambda separation energy of order 1 MeV.
Permanent Link: http://hdl.handle.net/11104/0300496