Pairing in the continuum: the quadrupole response of the Borromean nucleus 6He

Abstract

The ground state and low-lying continuum states of 6He are found within a shell model scheme, in a basis of two-particle states built out of continuum p-states of the unbound 5He nucleus, using a simple pairing contact-delta interaction. This accounts for the Borromean character of the bound ground state, revealing its composition. We investigate the quadrupole response of the system and we put our calculations into perspective with the latest experimental results. The calculated quadrupole strength distribution reproduces the narrow 2+ resonance, while a second wider peak is found at about 3.9 MeV above the g.s. energy.

arXiv comment5 pages, 5 figures

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• Investigation of contributions of the $2_2^{+}$ resonance in ${}^6$He via analysis of ${}^6$He($p$, $p^{\prime }$)
• Cooper pairs in the Borromean nuclei ${}^6$He and ${}^{11}$Li using continuum single particle level density
• Continuum discretized BCS approach for weakly bound nuclei
• Pairing enhancement in a two-neutron transfer process through the continuum
• Investigating the rate of ${}^{10}$Be(n,$\gamma$)${}^{11}$Be radiative capture reaction within the FRDWBA framework
• Two-cluster approach to the properties of one- and two-neutron-halo nuclei
• Deformation, halo, and bubble structure: A paradigm shift of exotic phenomena in light to medium mass nuclei
• Dineutron in the $2_1^{+}$ state of ${}^6$He
• Role of spd- Continuum Components in the Halo Nucleus 6He
• Resonances and collisional properties of neutron-rich helium isotopes in the adiabatic hyperspherical representation
• Correlation between the nuclear structure and reaction dynamics of Ar-isotopes as projectile using the relativistic mean-field approach
• Three-body Description of $2n$-Halo and Unbound $2n$-Systems: ${}^{22}$C and ${}^{26}$O
• Impact of uncertainties of unbound ${}^{10}$Li on the ground state of two-neutron halo ${}^{11}$Li