Description of proton-rich nuclei in the A≈20 region within the Gamow shell model

Abstract

The Gamow shell model is utilized to describe nuclear observables of the weakly bound and resonance isotonic states of 16 O at proton drip-line. It is hereby shown that the presence of continuum coupling leads to complex Coulomb contributions in the spectrum of these isotones. The necessity to include the effects of three-body forces, either by a direct calculation or by adding an A-dependence to the nucleon-nucleon interaction, already noticed in other theoretical models, is pointed out. It is also demonstrated that our approach is predictive for reaction observables.

Proton decays in $^{16}$Ne and $^{18}$Mg and isospin-symmetry breaking in carbon isotopes and isotones

“…Note that 17 Ne is suspected to be a two-proton halo from recent experiments [33,34], supported by the GSM calculations done in this context [35]. Added to that, continuum coupling has been shown to act differently on ground and excited states of proton-rich nuclei [36]. While Coulomb energies in resonance ground states usually follow the same trend as that of well bound nuclei, namely the isobaric multiplet mass equation (IMME) [37][38][39], the Coulomb energies of excited states depart from the IMME due to their more extended wave functions in the pre-asymptotic region [36].…”

Recent Progress in Gamow Shell Model Calculations of Drip Line Nuclei

“…In practical calculations, however, we often truncate basis model spaces so that only two particles can occupy scattering states. It has been checked that this is sufficient to obtain converged results for both the energy and decay width of many-body states [5,38,54].…”

“…The long chain of calcium isotopes provides an ideal laboratory for both theoretical and experimental investigations of unstable isotopes. With two typical doubly magic isotopes, 40 Ca and 48 Ca, and two new magic isotopes discovered in the neutron-rich region, 52 Ca [90] and 54 Ca [91], the calcium chain is speculated to end the 70 Ca isotope. Its rich nuclear structure data [10] attract continued theoretical interest, especially using methods that include continuum coupling.…”

“…59 Ca is weakly unbound with a small one-neutron separation energy S n = −326 keV in our GSM calculations. For the two-neutron separation energy S 2n , the GSM calculations are performed with two different cores, 48 Ca and 54 Ca. For 56,58,60 Ca, the two calculations give similar results.…”

“…16 Ne and 18 Mg Unbound Nuclei Two-proton decay is one of the most important drip-line phenomena. It occurs in proton drip line nuclei, such as 48 Ni, 54 F, 54 Zn, 76 K, 16 Ne, and 19 Mg (see a review of this topic in Ref. [4] ).…”