Mass-15 nuclei and predicting narrow states beyond the proton drip line

TL;DR

This paper updates previous MCAS calculations of mass-15 nuclei, predicting narrow resonances beyond the proton drip line and analyzing spectra of isobars with a unified approach for neutron and proton cluster models.

Contribution

It refines the MCAS method predictions for mass-15 nuclei, including narrow resonances, and develops a consistent Hamiltonian for cluster models of these isobars.

Findings

Confirmed narrow resonance states in $^{15}$F with new data.

Predicted additional narrow states at higher energies.

Developed a unified cluster model Hamiltonian for mass-15 isobars.

Abstract

In a previous letter (Phys. Rev. Lett. 96, 072502 (2006)), the multi-channel algebraic scattering (MCAS) technique was used to calculate spectral properties for proton-unstable $^{15}$F and its mirror, $^{15}$C. MCAS achieved a close match to the then-new data for $p+^{14}$O elastic scattering and predicted several unusually narrow resonances at higher energies. Subsequently, such narrow resonance states were found. New cross section data has been published characterising the shape of the $J^\pi =\frac{1}{2}^-$ resonance. Herein we update that first MCAS analysis and its predictions. We also study the spectra of the set of mass-15 isobars, ${}^{15}$C, ${}^{15}$N, ${}^{15}$O, and ${}^{15}$F, using the MCAS method and seeking a consistent Hamiltonian for clusterisation with a neutron and a proton, separately, coupled to core nuclei ${}^{14}$C and ${}^{14}$O.