9,916 research outputs found

    Chern-Simons-fermion model of quarks

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    We propose an extension of the standard model where quarks are viewed as fermions with a ``bare'' integer (weak) hypercharge which is normalized with a fractional part created by a quantized topological Chern-Simons configuration of the weak gauge fields. Consistency with hypercharge patterns not included in the standard model is shown.Comment: 4 pages, Revtex, no figure

    Neutrino mass generation with extra right-handed fields in a Dirac scenario via the type-I seesaw mechanism

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    An extension of the Standard Model (SM) is studied in which two right-handed (RH) neutrinos per generation are incorporated, but considering the hypothesis of the symmetry of lepton and quark contents in order to deprive the number of RH neutrinos of freedom, generate Dirac neutrinos and accommodate naturally tiny values for their masses. The high scale type-I seesaw regime is applied to the first, ordinary RH neutrino, whereas a low scale pseudo-Dirac scenario is used for the second, adulterant RH neutrino, implying that the first RH neutrino decouples at the high scale, while the second RH neutrino survives down to the low scale to pair off in a Dirac-like form with the corresponding left-handed (LH) neutrino. The small mass and couplings of this extra RH neutrino are explained by means of the statement of the symmetry of fermionic content, only regarded as a guideline to the natural choice of parameters since it is not a proper symmetry in the Lagrangian.Comment: 12 page

    Unification of standard and exotic matter through a Z2Z_2 symmetry

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    We consider a scenario in which the discrete weak symmetry between quarks and leptons is extended to the weak force by introducing exotic partners. We conjecture that there exists a hidden discrete symmetry P~\tilde{P}, defining a Z2Z_2 group, between standard and exotic quarks and leptons. The unified model SU(3)q×SU(3)q~×SU(2)q~×SU(2)q~×U(1)Y×P~SU(3)_{q} \times SU(3)_{\tilde{q}} \times SU(2)_{q \tilde{\ell}} \times SU(2)_{\tilde{q} \ell} \times U(1)_{Y} \times \tilde{P} is discussed, where the unifying discrete symmetry extends over particles and forces. It is shown that the lighter neutral and charged weak bosons generated upon spontaneous symmetry breaking have the same properties as those of the standard model. Cabbibo-Kobayashi-Maskawa unitarity is used to set a mass of order 2.8 TeV for the nonstandard weak bosons, which do not exhibit quark-lepton universality. A grand unified theory of GUTq~×GUTq~×P~GUT_{q \tilde{\ell}} \times GUT_{\tilde{q} \ell} \times \tilde{P} type, with decay of exotic matter into standard matter and no decay of the ordinary nucleon, is put forward.Comment: 6 pages, no figure
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