Dipole excited states in ${}^{11}$Li with complex scaling

Abstract

The 1${}^{-}$ excitations of the three--body halo nucleus ${}^{11}$Li are investigated. We use adiabatic hyperspherical expansion and solve the Faddeev equations in coordinate space. The method of complex scaling is used to compute the resonance states. The Pauli forbidden states occupied by core neutrons are excluded by constructing corresponding complex scaled phase equivalent two-body potentials. We use a recently derived neutron--core interaction consistent with known structure and reaction properties of ${}^{10}$Li and ${}^{11}$Li. The computed dipole excited states with $J^{\pi }=1/2^{+}$, $J^{\pi }=3/2^{+}$, and $J^{\pi }=5/2^{+}$ have energies ranging from 0.6 MeV to 1.0 MeV and widths between 0.15 MeV and 0.65 MeV. We investigate the dependence of the complex energies of these states on the ${}^{10}$Li spectrum. The finite spin 3/2 of the core and the resulting core-neutron spin-spin interaction are important. The connection with Coulomb dissociation experiments is discussed and a need for better measurements is pointed out.

28 pages, 6 figures, Nuclear Physics A, in press

References in corpus (8)

• Three-body halos. V. Computations of continuum spectra for Borromean nuclei
• Halo Excitation of ${}^6$He in Inelastic and Charge-Exchange Reactions
• The ${}^{10}$Li spectrum and the ${}^{11}$Li properties
• Breakup Reactions of 11Li within a Three-Body Model
• Phase equivalent potentials for three-body halos
• Two-neutron removal reactions of 6He treated as a three-body halo
• Comprehensive calculations of three--body breakup cross sections
• Coulomb and nuclear breakup of three-body halo nuclei

Cited by in corpus (19)

• Roles of the tensor and pairing correlations on the halo formation in 11Li
• Three-body structure of the low-lying ${}^{17}$Ne-states
• Structure of low-lying 12C-resonances
• Relative production rates of ${}^6$He, ${}^9$Be, ${}^{12}$C in astrophysical environments
• Di-neutron clustering and deuteron-like tensor correlation in nuclear structure focusing on 11Li
• Three-body Coulomb breakup of 11Li in the complex scaling method
• Generalized contour deformation method in momentum space: two-body spectral structures and scattering amplitudes
• Unbound exotic nuclei studied by transfer to the continuum reactions
• Isovector and isoscalar dipole excitations in ${}^9$Be and ${}^{10}$Be studied with antisymmetrized molecular dynamics
• Neutron-${}^3$H potentials and the ${}^5$H-properties
• Spin-dependent effective interactions for halo nuclei
• Necessary conditions for accurate computations of three-body partial decay widths
• Three-body structure of ${}^{19}$B: Finite-range effects in two-neutron halo nuclei
• Anatomy of three-body decay II. Decay mechanism and resonance structure
• Three-body properties of low-lying ${}^{12}$Be resonances
• Efimov effect in nuclear three-body resonance decays
• ${}^{10}$Li spectrum from ${}^{11}$Li fragmentation
• Few-body structures in the mirror nuclei, ${}^{11}$O and ${}^{11}$Li
• Dineutron clusters in ${}^7$He and ${}^8$He structure