Spectroscopy of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mmultiscripts><mml:mi mathvariant="normal">Na</mml:mi><mml:mprescripts/><mml:none/><mml:mn>28</mml:mn></mml:mmultiscripts></mml:mrow></mml:math>: Shell evolution toward the drip line
Bibliographic record
Abstract
Excited states have been studied in $^{28}\mathrm{Na}$ using the $\ensuremath{\beta}$-decay of implanted $^{28}\mathrm{Ne}$ ions at the Grand Acc\'el\'erateur National d'Ions Lourds/LISE as well as the in-beam $\ensuremath{\gamma}$-ray spectroscopy at the National Superconducting Cyclotron Laboratory/S800 facility. New states of positive $({J}^{\ensuremath{\pi}}={3}^{+},{4}^{+})$ and negative $({J}^{\ensuremath{\pi}}={1}^{\ensuremath{-}}--{5}^{\ensuremath{-}})$ parity are proposed. The former arise from the coupling between $0{d}_{5/2}$ protons and $0{d}_{3/2}$ neutrons, while the latter are attributable to couplings of $0{d}_{5/2}$ protons with $1{p}_{3/2}$ or $0{f}_{7/2}$ neutrons. While the relative energies between the ${J}^{\ensuremath{\pi}}={1}^{+}--{4}^{+}$ states are well reproduced with the USDA interaction in the $N=17$ isotones, a progressive shift in the ground-state binding energy (by about 500 keV) is observed between $^{26}\mathrm{F}$ and $^{30}\mathrm{Al}$. This points to a possible change in the proton-neutron $0{d}_{5/2}\text{\ensuremath{-}}0{d}_{3/2}$ effective interaction when moving from stability to the drip line. The presence of ${J}^{\ensuremath{\pi}}={1}^{\ensuremath{-}}--{4}^{\ensuremath{-}}$ negative-parity states around 1.5 MeV as well as of a candidate for a ${J}^{\ensuremath{\pi}}={5}^{\ensuremath{-}}$ state around 2.5 MeV give further support to the collapse of the $N=20$ gap and to the inversion between the neutron $0{f}_{7/2}$ and $1{p}_{3/2}$ levels below $Z=12$. These features are discussed in the framework of shell-model and energy-density-functional calculations, leading to predicted negative-parity states in the low-energy spectra of the $^{26}\mathrm{F}$ and $^{25}\mathrm{O}$ nuclei.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.020 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".