Eur. Phys. J. A (2021) 57: 165
https://doi.org/10.1140/epja/s10050-021-00479-8

Regular Article - Theoretical Physics

Low-energy spectra of mirror mass-19 nuclei with a collective coupled-channel scattering model

¹ School of Physics, University of Melbourne, 3010, Victoria, Australia
² Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park, 2006, Johannesburg, South Africa
³ School of Science/Learning and Teaching Group, The University of New South Wales, ACT 2600, Canberra, Australia
⁴ Istituto Nazionale di Fisica Nucleare, Sezione di Padova, 35131, Padova, Italia

^a amos@unimelb.edu.au

Received: 4 January 2021
Accepted: 29 April 2021
Published online: 16 May 2021

Abstract

The spectra of mass-19 nuclei are unusual and pose a challenge for theoretical models of their structure. Herein the Multi-Channel Algebraic Scattering (MCAS) method has been used with a collective (vibrational model) description of the low-excitation states of O and Ne to describe the spectra of four mass-19 nuclei, specifically the mirror pairs (O, Na) and (F, Ne). This coupled-channel approach allows for the effects of the Pauli principle to be included using non-local orthogonalizing pseudo-potentials. By the coupling of neutrons to the core nuclei, we obtain states in O (a neutron coupled to O) and Ne (a neutron coupled to Ne). Mirror symmetry and addition of the Coulomb interaction gives states in F (a proton coupled to O) and Na (a proton coupled to Ne). However, the same compound nuclei may be described as the coupling of more complicated nuclear clusters. We obtain the states in F as the coupling of an to N, as well as the coupling of H to O. Similarly, states in Ne have been obtained from the coupling of an to O and of the coupling of He to O. Finally, as the method allows extraction of scattering matrices, it has been used to evaluate cross sections for the elastic scattering of low-energy neutrons from O and of low-energy particles from O.