Binding energies of λλ hypernuclei and the λλ interaction
1984; Elsevier BV; Volume: 422; Issue: 3 Linguagem: Inglês
10.1016/0375-9474(84)90362-2
ISSN1873-1554
AutoresA.R. Bodmer, Q. N. Usmani, J. Carlson,
Tópico(s)Superconducting Materials and Applications
ResumoThe binding energies of the ΛΛ hypernuclei 10ΛΛBe and 6ΛΛHe are calculated variationally with a 2α + 2Λ and with an α + 2Λ model, respectively. For 10ΛΛBe the integrations were made with Monte Carlo techniques while for 6ΛΛHe direct numerical methods were used. A wide range of phenomenological ΛΛ potentials based on meson-exchange models was considered. An approximately universal linear relation between the calculated values of BΛΛ(10ΛΛBe) and of BΛΛ(6ΛΛHe) is obtained. For the experimental value of BΛΛ(10ΛΛBe) = 17.7 ± 0.1 MeV this relation predicts a much too small value of BΛΛ(6ΛΛHe), well below the lower limit of the quoted experimental value of 10.9 ± 0.6 MeV. For ΛΛ potentials with repulsive cores the relations, for a given BΛΛ(10ΛΛBe), between the low-energy ΛΛ scattering parameters a, r0 and the intrinsic range b are both approximately universal and independent of the detailed potential shape. For the experimental value of BΛΛ(10ΛΛBe) the preferred values are 2.5 ≲ −a ≲ 3.5 fm, 2.6 ≲ r0 ≲ 3.1 fm. The large and negative values of a correspond to conditions not too far from a bound 1S0 ΛΛ state and could indicate a 6-quark dibaryon state with the same quantum numbers and above the ΛΛ threshold.
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