Binding energies of light, A ≤ 6, ΛΛ hypernuclei are calculated using the stochastic variational method in a pionless effective field theory (/ πEFT) approach at leading order with the purpose of assessing critically the onset of binding in the strangeness S = −2 hadronic sector. The / πEFT 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 6 ΛΛ He. The recently debated neutral three-body and four-body systems 3 ΛΛ n and 4 ΛΛ n are found unbound by a wide margin. A relatively large value of |aΛΛ| 1.5 fm is needed to bind 4 ΛΛ H, thereby questioning its particle stability. In contrast, the particle stability of the A = 5 ΛΛ hypernuclear isodoublet 5 ΛΛ H-5 ΛΛ He is robust, with Λ separation energy of order 1 MeV. PACS numbers: Introduction. Single-Λ and double-Λ (ΛΛ) hypernuclei provide a unique extension of nuclear physics into strange hadronic matter [1]. Whereas the behavior of a single Λ hyperon in atomic nuclei has been deduced quantitatively by studying Λ hypernuclei ( A Λ Z) from A=3 to 208 [2], only three ΛΛ hypernuclei ( A ΛΛ Z) are firmly established: the lightest known 6 ΛΛ He Nagara event [3] and two heavier ones, 10 ΛΛ Be and 13 ΛΛ B [4]. Remarkably, their binding energies come out consistently in shell-model calculations [5]. Few ambiguous emulsion events from KEK [6] and J- PARC [7] have also been reported. However, and perhaps more significant is the absence of any good data on the onset of ΛΛ hypernuclear binding for A < 6. In distinction from the heavier species, these very light s-shell species, if bound, could be more affected by microscopic strangeness S = −2 dynamics. An obvious issue is the effect of a possible ΞN dominated H dibaryon resonance some 20-30 MeV above the ΛΛ threshold [8,9] on ΛΛ hypernuclear binding in general.Several calculations of light A < 6 s-shell ΛΛ hypernuclei using ΛΛ interactions fitted to 6 ΛΛ He suggest a fairly weak ΛΛ interaction, with the onset of ΛΛ hypernuclear binding defered to A = 4. Indeed, a slightly bound I = 0
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.