2018 Impact factor 2.481
Hadrons and Nuclei
Eur. Phys. J. A 17, 19-24 (2003)
DOI: 10.1140/epja/i2002-10136-3

Neutron halos in hypernuclei

H.F. Lü1, J. Meng1, 2, 3, S.Q. Zhang1 and S.-G. Zhou1, 2, 3

1  School of Physics, Peking University, Beijing 100871, PRC
2  Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100080, PRC
3  Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000, PRC

mengj@pku.edu.cn

(Received: 21 October 2002 / Revised version: 11 January 2003 / Published online: 8 April 2003)

Abstract
Properties of single- ${\rm\Lambda}$ and double- ${\rm\Lambda}$ hypernuclei for even- N Ca isotopes ranging from the proton dripline to the neutron dripline are studied using the relativistic continuum Hartree-Bogoliubov theory with a zero-range pairing interaction. Compared with ordinary nuclei, the addition of one or two ${\rm\Lambda}$-hyperons lowers the Fermi level. The predicted neutron dripline nuclei are, respectively, $\chem{^{75}_{\Lambda}Ca}$ and $\chem{^{76}_{2\Lambda}Ca}$, as the additional attractive force provided by the ${\rm\Lambda}$-N interaction shifts nuclei from outside to inside the dripline. Therefore, the last bound hypernuclei have two more neutrons than the corresponding ordinary nuclei. Based on the analysis of two-neutron separation energies, neutron single-particle energy levels, the contribution of continuum and nucleon density distribution, giant halo phenomena due to the pairing correlation, and the contribution from the continuum are suggested to exist in Ca hypernuclei similar to those that appear in ordinary Ca isotopes.

PACS
21.10.Gv - Mass and neutron distributions.
21.60.-n - Nuclear-structure models and methods.
21.60.Jz - Hartree-Fock and random-phase approximations.
21.80.+a - Hypernuclei.

© Società Italiana di Fisica, Springer-Verlag 2003