Prediction of exotic hyperon halos in neutron-rich Zr hypernuclei

Abstract

We study the single- and double-Λ hypernuclei in Zr isotopes by Hartree-Fock-Bogoliubov model with Skyrme-type nucleon-nucleon, Λ-nucleon, and Λ-Λ interactions. We found two peculiar features of the Λ hyperon halo phenomena, which were never found in nuclei without the strangeness degree of freedom. One is the d-wave halo, and the other is the bunch of three halo orbits just below the Λ hyperon threshold in $^{137}_\Lambda$Zr and also $^{138}_{\Lambda \Lambda }$Zr. We name these exotic halo phenomena “ giant hyperon halo” in the hypernuclei whose core nucleus 136Zr was predicted to have “ giant neutron halo”. The interaction between Λ hyperons and the neutrons is responsible to induce the giant hyperon halo phenomena in the single- and double-Λ nuclei, $^{137}_\Lambda$Zr and $^{138}_{\Lambda \Lambda }$Zr.

Density-dependent relativistic mean field approach and its application to single-Λ hypernuclei in oxygen hyperisotopes*

“…The multidimensionally constrained RMF model has been used to study the shape evolution of hypernuclei in argon hyperisotopes [54]. The beyond meanfield approach has been utilized to discuss the evolution of p-state energies and composition in carbon hyperisotopes [24], as well as the hyperon halo structures in boron and carbon hyperisotopes [27,29]. These studies revealed the significance of the role of isospin in the description of hypernuclear structure.…”

“…The integration can be computed using the radial wave functions of the initial and final single-Λ states (see Ref. [27] for details).…”