{
  "abstract": "The structure of the neutron-rich nucleus $^{21}$B is investigated within a three-body model consisting of a $^{19}$B core and two neutrons. The three-body wave functions are computed using the hyperspherical adiabatic expansion method combined with the complex-scaling technique. Four potential parametrizations compatible with the available experimental information on $^{20}$B are considered. The calculations predict a low-lying $\\frac{3}{2}^-$ state below the experimentally observed resonance at 2.47~MeV. An analysis of the dependence on the three-body interaction shows that this state cannot be shifted to the experimental resonance energy; instead, it remains either bound or becomes a near-threshold resonance with a rapidly increasing width. These results indicate that the observed resonance is more naturally interpreted as the second $\\frac{3}{2}^-$ state, whereas a lower-lying $\\frac{3}{2}^-$ state, dominated by an $s_{1/2}$ configuration, has so far eluded experimental observation. Momentum correlations are obtained for the experimentally observed resonance. In addition, the existence of other resonances is investigated.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.32714",
  "author_total": 2,
  "authors": [
    {
      "name": "R. Alvarez-Rodriguez"
    },
    {
      "name": "E. Garrido"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8vy1qmpc9gddm.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.32714",
  "fulltext_url": null,
  "id": "8vy1qmpc9gddm",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.32714",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "openalex",
      "3106|Nuclear physics research studies"
    ]
  ],
  "openalex": "W7214767156",
  "pdf_url": "https://arxiv.org/pdf/2609.32714",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8vy1qmpc9gddm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:12Z",
      "native_id": "2609.32714",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.32714"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "Structure and decay of $^{21}$B resonances",
  "title_text": "Structure and decay of ^21B resonances",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:12Z",
  "url": "https://research.draconitic.com/paper/8vy1qmpc9gddm",
  "venue": "arXiv",
  "versions": []
}