1,217 research outputs found

    Fermion Generations and Mixing from Dualized Standard Model

    Get PDF
    We review a possible solution to the fermion generation puzzle based on a nonabelian generalization of electric--magnetic duality derived some years ago. This nonabelian duality implies the existence of another SU(3) symmetry dual to colour, which is necessarily broken when colour is confined and so can play the role of the ``horizontal'' symmetry for fermion generations. When thus identified, dual colour then predicts 3 and only 3 fermion generations, besides suggesting a special Higgs mechanism for breaking the generation symmetry. A phenomenological model with a Higgs potential and a Yukawa coupling constructed on these premises is shown to explain immediately all the salient qualitative features of the fermion mass hierarchy and mixing pattern, excepting for the moment CP-violation. Calculations already carried out to 1-loop order is shown to give with only 3 adjustable parameters the following quantities all to within present experimental error: all 9 CKM matrix elements ∣Vrs∣|V_{rs}| for quarks, the neutrino oscillation angles or the MNS lepton mixing matrix elements ∣Uμ3∣,∣Ue3∣|U_{\mu 3}|, |U_{e 3}|, and the mass ratios mc/mt,ms/mb,mμ/mτm_c/m_t, m_s/m_b, m_\mu/m_\tau. The special feature of this model crucial for deriving the above results is a fermion mass matrix which changes its orientation (rotates) in generation space with changing energy scale, a feature which is shown to have direct empirical support.Comment: updated version of course of lectures given at the 42nd Cracow School of Theoretical Physics, 2002, Polan

    On the Corner Elements of the CKM and PMNS Matrices

    Get PDF
    Recent experiments show that the top-right corner element (Ue3U_{e3}) of the PMNS, like that (VubV_{ub}) of the CKM, matrix is small but nonzero, and suggest further via unitarity that it is smaller than the bottom-left corner element (Uτ1U_{\tau 1}), again as in the CKM case (Vub<VtdV_{ub} < V_{td}). An attempt in explaining these facts would seem an excellent test for any model of the mixing phenomenon. Here, it is shown that if to the assumption of a universal rank-one mass matrix, long favoured by phenomenologists, one adds that this matrix rotates with scale, then it follows that (A) by inputting the mass ratios mc/mt,ms/mb,mμ/mτm_c/m_t, m_s/m_b, m_\mu/m_\tau, and m2/m3m_2/m_3, (i) the corner elements are small but nonzero, (ii) Vub<VtdV_{ub} < V_{td}, Ue3<Uτ1U_{e 3} < U_{\tau 1}, (iii) estimates result for the ratios Vub/VtdV_{ub}/V_{td} and Ue3/Uτ1U_{e 3}/U_{\tau 1}, and (B) by inputting further the experimental values of Vus,VtbV_{us}, V_{tb} and Ue2,Uμ3U_{e2},U_{\mu 3}, (iv) estimates result for the values of the corner elements themselves. All the inequalities and estimates obtained are consistent with present data to within expectation for the approximations made.Comment: 9 pages, 2 figures, updated with new experimental data and more detail

    A Model Behind the Standard Model

    Get PDF
    In spite of its many successes, the Standard Model makes many empirical assumptions in the Higgs and fermion sectors for which a deeper theoretical basis is sought. Starting from the usual gauge symmetry u(1)×su(2)×su(3)u(1) \times su(2) \times su(3) plus the 3 assumptions: (A) scalar fields as vielbeins in internal symmetry space \cite{framevec}, (B) the ``confinement picture'' of symmetry breaking \cite{tHooft,Banovici}, (C) generations as ``dual'' to colour \cite{genmixdsm}, we are led to a scheme which offers: (I) a geometrical significance to scalar fields, (II) a theoretical criterion on what scalar fields are to be introduced, (III) a partial explanation of why su(2)su(2) appears broken while su(3)su(3) confines, (IV) baryon-lepton number (B - L) conservation, (V) the standard electroweak structure, (VI) a 3-valued generation index for leptons and quarks, and (VII) a dynamical system with all the essential features of an earlier phenomenological model \cite{genmixdsm} which gave a good description of the known mass and mixing patterns of quarks and leptons including neutrino oscillations. There are other implications the consistency of which with experiment, however, has not yet been systematically explored. A possible outcome is a whole new branch of particle spectroscopy from su(2)su(2) confinement, potentially as rich in details as that of hadrons from colour confinement, which will be accessible to experiment at high energy.Comment: 66 pages, added new material on phenomenology, and some new reference

    A Nonabelian Yang-Mills Analogue of Classical Electromagnetic Duality

    Get PDF
    The classic question of a nonabelian Yang-Mills analogue to electromagnetic duality is here examined in a minimalist fashion at the strictly 4-dimensional, classical field and point charge level. A generalisation of the abelian Hodge star duality is found which, though not yet known to give dual symmetry, reproduces analogues to many dual properties of the abelian theory. For example, there is a dual potential, but it is a 2-indexed tensor TμνT_{\mu\nu} of the Freedman-Townsend type. Though not itself functioning as such, TμνT_{\mu\nu} gives rise to a dual parallel transport, A~μ\tilde{A}_\mu, for the phase of the wave function of the colour magnetic charge, this last being a monopole of the Yang-Mills field but a source of the dual field. The standard colour (electric) charge itself is found to be a monopole of A~μ\tilde{A}_\mu. At the same time, the gauge symmetry is found doubled from say SU(N)SU(N) to SU(N)×SU(N)SU(N) \times SU(N). A novel feature is that all equations of motion, including the standard Yang-Mills and Wong equations, are here derived from a `universal' principle, namely the Wu-Yang (1976) criterion for monopoles, where interactions arise purely as a consequence of the topological definition of the monopole charge. The technique used is the loop space formulation of Polyakov (1980).Comment: We regret that, due to a technical hitch, parts of the reference list were mixed up. This is the corrected version. We apologize to the authors whose papers were misquote
    • …
    corecore