{
  "id": "1206.3878",
  "version": "v3",
  "published": "2012-06-18T10:30:23.000Z",
  "updated": "2013-01-04T13:11:12.000Z",
  "title": "On the Correlations between Flavour Observables in Minimal U(2)^3 Models",
  "authors": [
    "Andrzej J. Buras",
    "Jennifer Girrbach"
  ],
  "comment": "28 pages, 6 figures; v2: Few references and discussion on CP violation in B_s-> mu^+ mu^- added; v3: Several clarifying comments added, conclusions unchanged, version accepted for publication in JHEP",
  "categories": [
    "hep-ph",
    "hep-ex",
    "hep-lat"
  ],
  "abstract": "The stringent correlations between flavour observables in models with CMFV are consistent with the present data except for the correlation Delta M_{s,d}-epsilon_K. Motivated by the recent work of Barbieri et al, we compare the CMFV correlations with the ones present in a special class of models with an approximate global U(2)^3 flavour symmetry, constrained by a minimal set of spurions governing the breakdown of this symmetry and the assumption that only SM operators are relevant in flavour physics. This analog of CMFV to be called MU(2)^3 allows to avoid the Delta M_{s,d}-epsilon_K tension in question because of reduced flavour symmetry and implied non-MFV contributions to Delta M_{s,d}. While the patterns of flavour violation in K meson system is the same as in CMFV models, the CP-violation in B_{s,d} meson systems can deviate from the one in the SM and CMFV models. We point out a stringent triple S_{psi K_S}-S_{psi phi}-|V_ub| correlation in this class of models that could in the future provide a transparent distinction between different MU(2)^3 models and in the context of these models determine |V_ub| by means of precise measurements of S_{psi K_S} and S_{psi phi} with only small hadronic uncertainties. For fixed S_{psi K_S} the correlation between B(B^+ -> tau^+nu_tau) and S_{psi phi} follows. We also find that MU(2)^3 models could in principle accommodate a negative value of S_{psi phi}, provided |V_ub| is found to be in the ballpark of exclusive determinations and the particular MU(2)^3 model provides a 25% enhancement of epsilon_K. A supersymmetric U(2)^3 model worked out in the Barbieri-School appears to satisfy these requirements. However if B(B^+ -> tau^+nu_tau)>1.0 10^{-4} will be confirmed by future experiments only positive S_{psi phi} is allowed in this framework. We summarize briefly the pattern of flavour violation in rare K and B_{s,d} decays in MU(2)^3 models.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2013-01-04T13:11:12.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "flavour observables",
      "flavour violation",
      "flavour symmetry",
      "meson system",
      "cmfv models"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1007/JHEP01(2013)007",
      "journal": "Journal of High Energy Physics",
      "year": 2013,
      "month": "Jan",
      "volume": 2013,
      "pages": 7
    },
    "note": {
      "typesetting": "TeX",
      "pages": 28,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1118575,
      "adsabs": "2013JHEP...01..007B"
    }
  }
}