Structure and decay of the pygmy dipole resonance in 26Ne

Abstract

The low-lying spectra of ${}^{24,25,26}\mathrm{Ne}$ and the structure of the pygmy dipole resonance (PDR) in ${}^{26}\mathrm{Ne}$ have been theoretically studied by the antisymmetrized molecular dynamics (AMD) and its extended version called shifted-basis AMD. The calculated energy and strength of the PDR reasonably agree with the observation, and the analysis of the wave function shows that the PDR is dominated by neutron excitation coupled to the quadrupole excited core nucleus ${}^{25}\mathrm{Ne}$, which explains the observed unexpected decay of PDR to the excited states of ${}^{25}\mathrm{Ne}$. The large isoscalar component of PDR is also shown and the enhancement of the core excitation in neutron-rich Ne isotopes is conjectured.

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Cited by in corpus (10)

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• Isoscalar dipole excitations in ${}^{16}$O
• Cluster and toroidal aspects of isoscalar dipole excitations in ${}^{12}$C
• Microscopic study of the deformed neutron halo of 31Ne
• Soft breathing modes in neutron--rich nuclei with the subtracted second random--phase approximation
• Electric dipole response of sd-shell nuclei within the Configuration-Interaction Shell Model approach
• Description of isospin mixing by a generator coordinate method
• Modeling Ultra-High-Energy Cosmic Rays propagation using the input from Configuration Interaction Shell Model