{
  "id": "hep-ph/9610449",
  "version": "v1",
  "published": "1996-10-23T01:25:48.000Z",
  "updated": "1996-10-23T01:25:48.000Z",
  "title": "Unified Theories with U(2) Flavor Symmetry",
  "authors": [
    "R. Barbieri",
    "L. J. Hall",
    "S. Raby",
    "A. Romanino"
  ],
  "comment": "31 pages, 3 .eps figures included",
  "journal": "Nucl.Phys. B493 (1997) 3-26",
  "doi": "10.1016/S0550-3213(97)00134-X",
  "categories": [
    "hep-ph"
  ],
  "abstract": "A general operator expansion is presented for quark and lepton mass matrices in unified theories based on a U(2) flavor symmetry, with breaking parameter of order $V_{cb} \\approx m_s/m_b \\approx \\sqrt{m_c/m_t}$. While solving the supersymmetric flavor-changing problem, a general form for the Yukawa couplings follows, leading to 9 relations among the fermion masses and mixings, 5 of which are precise. The combination of grand unified and U(2) symmetries provides a symmetry understanding for the anomalously small values of $m_u/m_c$ and $m_c/m_t$. A fit to the fermion mass data leads to a prediction for the angles of the CKM unitarity triangle, which will allow a significant test of these unified U(2) theories. A particular SO(10) model provides a simple realization of the general operator expansion. The lighter generation masses and the non-trivial structure of the CKM matrix are generated from the exchange of a single U(2) doublet of heavy vector generations. This model suggests that CP is spontaneously broken at the unification scale --- in which case there is a further reduction in the number of free parameters.",
  "revisions": [
    {
      "version": "v1",
      "updated": "1996-10-23T01:25:48.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "11.30.Hv",
      "12.15.Ff",
      "12.10.-g"
    ],
    "keywords": [
      "flavor symmetry",
      "unified theories",
      "general operator expansion",
      "heavy vector generations",
      "fermion mass data"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "Elsevier",
      "journal": "Nucl. Phys. B"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 31,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 425001
    }
  }
}