Two-neutron correlations in a Borromean ${}^{20}\mathrm{C}+n+n$ system: Sensitivity of unbound subsystems

Abstract

The structure of ${}^{22}$C plays a vital role in the new physics at subshell closure of $N=16$ in the neutron-rich region. We study the two-neutron correlations in the ground state of the weakly-bound Borromean nucleus ${}^{22}$C sitting at the edge of the neutron-drip line and its sensitivity to $\mathrm{core}$-$n$ potential. For the present study, we employ a three-body ($\mathrm{core}+n+n$) structure model designed for describing the Borromean system by explicit coupling of unbound continuum states of the subsystem ($\mathrm{core}+n$). We use a density-independent contact-delta interaction to describe the neutron-neutron interaction and its strength is varied to fix the binding energy. Along with the ground-state properties of ${}^{22}$C, we investigate its electric-dipole and monopole responses, discussing the contribution of various configurations. Our results indicate more configuration mixing as compared to the previous studies in the ground state of ${}^{22}$C. However, they strongly depend upon the choice of the ${}^{20}\mathrm{C}$-$n$ potential as well as the binding energy of ${}^{22}$C, which call for new precise measurements for the low-lying continuum structure of the binary system (${}^{20}\mathrm{C}+n$) and the mass of ${}^{22}$C. These measurements will be essential to understand the Borromean three-body system ${}^{22}$C with more accuracy.

arXiv comment13 pages, 6 figures, To appear in Few-Body Systems (2019)

References in corpus (20)

• Pairing correlations in nuclei on the neutron-drip line
• Reaction cross sections of carbon isotopes incident on a proton
• Direct mass measurements of 19B, 22C, 29F, 31Ne, 34Na and other light exotic nuclei
• Systematic analysis of reaction cross sections of carbon isotopes
• ${}^{22}$C: $S$-Wave Two-Neutron Halo
• Shrunk halo and quenched shell gap at $N=16$ in ${}^{22}$C: Inversion of $sd$ states and deformation effects
• One- and two-neutron removal reactions from the most neutron-rich carbon isotopes
• Implications of a matter-radius measurement for the structure of Carbon-22
• Constraints on two-neutron separation energy in the Borromean ${}^{22}$C nucleus
• Search for ${}^{21}$C and constraints on ${}^{22}$C
• Examination of the ${}^{22}$C radius determination with interaction cross sections
• Structure of and E2 transition in ${}^{16}$C in a ${}^{14}$C+n+n model
• Pairing in the continuum: the quadrupole response of the Borromean nucleus 6He
• Electric multipole response of the halo nucleus ${}^6$He
• Interplay between the 0+_2 resonance and the nonresonant continuum of the drip-line two-neutron halo nucleus 22C
• Intermediate energy four-body breakup calculations for 22C
• Two-neutron halo nuclei in one dimension: dineutron correlation and breakup reaction
• Mean-field analysis of ground state and low-lying electric dipole strength in ${}^{22}$C
• Coulomb breakup of 22C in a four-body model
• New experiments demand for a more precise analysis of continuum spectrum in 6He: technical details and formalism

Cited by in corpus (7)

• Core swelling in spherical nuclei: An indication of the saturation of nuclear density
• Investigating the rate of ${}^{10}$Be(n,$\gamma$)${}^{11}$Be radiative capture reaction within the FRDWBA framework
• Deformation, halo, and bubble structure: A paradigm shift of exotic phenomena in light to medium mass nuclei
• Two-cluster approach to the properties of one- and two-neutron-halo nuclei
• Impact of uncertainties of unbound ${}^{10}$Li on the ground state of two-neutron halo ${}^{11}$Li
• Three-body Description of $2n$-Halo and Unbound $2n$-Systems: ${}^{22}$C and ${}^{26}$O
• An overview of the scientific contribution of Andrea Vitturi to Nuclear Physics (being an account of the recent TNP19 meeting held in Padova)