{
  "id": "1503.01687",
  "version": "v1",
  "published": "2015-03-05T16:58:39.000Z",
  "updated": "2015-03-05T16:58:39.000Z",
  "title": "Charge symmetry breaking in $Λ$ hypernuclei revisited",
  "authors": [
    "Avraham Gal"
  ],
  "comment": "to be submitted soon, comments are welcome",
  "categories": [
    "nucl-th",
    "hep-ph",
    "nucl-ex"
  ],
  "abstract": "The large charge symmetry breaking (CSB) implied by the $\\Lambda$ binding energy difference $\\Delta B^{4}_{\\Lambda}(0^+_{\\rm g.s.})\\equiv B_{\\Lambda}(_{\\Lambda}^4$He)$-$$B_{\\Lambda}(_{\\Lambda}^4$H) = 0.35$\\pm$0.06 MeV of the $A=4$ mirror hypernuclei ground states, determined from emulsion studies, has defied theoretical attempts to reproduce it in terms of CSB in hyperon masses and in hyperon-nucleon interactions, including one pion exchange arising from $\\Lambda-\\Sigma^0$ mixing. Using a schematic strong-interaction $\\Lambda N\\leftrightarrow\\Sigma N$ coupling model developed by Akaishi and collaborators for $s$-shell $\\Lambda$ hypernuclei, we revisit the evaluation of CSB in the $A=4$ $\\Lambda$ hypernuclei and extend it to $p$-shell mirror $\\Lambda$ hypernuclei. The model yields values of $\\Delta B^{4}_{\\Lambda} (0^+_{\\rm g.s.})\\sim 0.25$ MeV. Smaller size and mostly negative $p$-shell binding energy differences are calculated for the $A=7-10$ mirror hypernuclei, in rough agreement with the few available data. CSB is found to reduce by almost 30 keV the 110 keV $_{~\\Lambda}^{10}$B g.s. doublet splitting anticipated from the hyperon-nucleon strong-interaction spin dependence, thereby explaining the persistent experimental failure to observe the $2^-_{\\rm exc}\\to 1^-_{\\rm g.s.}$ $\\gamma$-ray transition.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-03-05T16:58:39.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "hypernuclei",
      "large charge symmetry breaking",
      "binding energy difference",
      "transition"
    ],
    "publication": {
      "doi": "10.1016/j.physletb.2015.04.009"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2015arXiv150301687G",
      "inspire": 1347399
    }
  }
}