Isobaric Analog States and Coulomb Displacement Energies in the (1d52) Shell

Abstract

The (p, t) and (p, 3 He) reactions have been used to locate three previously unknown T~\ isobaric analog states in 19 F, 19 Ne,and 23 Mg, in addition to significantly improving the precision on the energies of the T= f state in 23 Na and the T = 2 states in 20 F and 24 Na. These multiplets all lie within the " (ld m ) shell" in that they have fewer than n=12 nucleons outside 16 0, and r<minimum (\n, 6-\n). Including these data, twenty-eight displacement energies are now known throughout this shell for all possible multiplets with T<2 (except T-2, mass-22). The experimental displacement energies were compared in detail with calculations which used Hecht's Coulomb-energy equations; the excellent agreement obtained appeared to be relatively insensitive to the assumed nuclear wave functions since both the low-seniority j-j coupling limit and the Wigner supermultiplet scheme produced similar results. Four parameters related to the twobody Coulomb-energy matrix elements were treated as adjustable in fitting the data but their final values are in reasonable agreement with matrix elements calculated using harmonic-oscillator wave functions. A fifth adjustable parameter took account of the Z and N dependence of the charge radius. Using the experimental parameters, the unmeasured masses of 19 Na, 20 Mg, 21 Mg, 22 A1, 23 A1, 24 Si, and 25 Si are predicted, together with the excitation energies of unobserved analog states in the 1^5/2 shell.

β-Delayed Proton Emission ofAl23

“…The assumed ground-state spin of | + is based on its mirror 23 Ne; other data in the figure are from Hardy et aZ. 7 and Haun and Robertson. 8 The superallowed j3 decay of nuclides in the mass series A = 4^ + 3, T 2 = - § leads to levels in their daughters which are very close to the proton separation energy.…”

Spectroscopic study of Ne20+p reactions using the JENSA gas-jet target to constrain the astrophysical F18Bardayan1, Chipps2, Ahn3 et al. 2017Phys. Rev. C5010View full textAdd to dashboardCite

“…by a level density resolvable within the energy resolution of the system (∼ 60 keV). While there has been a single previous study of the 20 Ne(p, 3 He) 18 F reaction [28], a spectroscopic study of the levels populated in the reaction has not been previously reported. Similar to the 20 Ne(p, d) 19 Ne data, events associated with 3 He ejectiles were selected in software for analysis.…”

Analysis of Coulomb displacement energies and its relation to the proton halo structure of nuclei

“…ref. [6]), and this triplet has therefore been excluded from a shell model analysis of Coulomb displacement energies [6,8]. The admixture of different shells is one of the possible explanations of this anomaly [6].…”