25,220 research outputs found

    Phase Transition Couplings in the Higgsed Monopole Model

    Get PDF
    Using a one-loop approximation for the effective potential in the Higgs model of electrodynamics for a charged scalar field, we argue for the existence of a triple point for the renormalized (running) values of the selfinteraction λ\lambda and the "charge" g given by (λrun,g2)=(−10/9π2,4/35/3π2)≈(−11,17)(\lambda_{run}, g^2) = (-{10/9} \pi^2,{4/3}\sqrt{{5/3}}{\pi^2}) \approx(-11, 17). Considering the beta-function as a typical quantity we estimate that the one-loop approximation is valid with accuracy of deviations not more than 30% in the region of the parameters: 0.2∼<α,α~∼<1.35.0.2 \stackrel{<}{\sim}{\large \alpha, \tilde{\alpha}} \stackrel{<}{\sim}1.35. The phase diagram given in the present paper corresponds to the above-mentioned region of α,α~\alpha, \tilde \alpha. Under the point of view that the Higgs particle is a monopole with a magnetic charge g, the obtained electric fine structure constant turns out to be αcrit≈0.185\alpha_{crit}\approx{0.18_5} by the Dirac relation. This value is very close to the αcritlat≈0.20\alpha_{crit}^{lat}\approx{0.20} which in a U(1) lattice gauge theory corresponds to the phase transition between the "Coulomb" and confinement phases. Such a result is very encouraging for the idea of an approximate "universality" (regularization independence) of gauge couplings at the phase transition point. This idea was suggested by the authors in their earlier papers.Comment: 27 pages, 3 figure

    Standard Model and Graviweak Unification with (Super)Renormalizable Gravity. Part I: Visible and Invisible Sectors of the Universe

    Full text link
    We develop a self-consistent Spin(4,4)Spin(4,4)-invariant model of the unification of gravity with weak SU(2)SU(2) gauge and Higgs fields in the visible and invisible sectors of our Universe. We consider a general case of the graviweak unification, including the higher-derivative super-renormalizable theory of gravity, which is a unitary, asymptotically-free and perturbatively consistent theory of the quantum gravity.Comment: 27 page

    Generalized dual symmetry of nonabelian theories, monopoles and dyons

    Full text link
    In the present talk we present an investigation of nonabelian SU(N) gauge theories, describing a system of fields with non--dual g and dual \tilde g charges and revealing the generalized dual symmetry. The Zwanziger type action is suggested. The renormalization group equations for pure nonabelian theories, in particular for pure SU(3)\times\widetilde{SU(3)} gauge theory (as an example) are analysed. We consider not only monopoles, but also dyons. The behaviour of the QCD total beta--function is investigated. It was shown that this beta--function is antisymmetric under the interchange \alpha\leftrightarrow\frac 1\alpha (here \alpha\equiv\alpha_s), and has zero ("fixed point") at \alpha = 1. Monopoles, or dyons, are responsible for the phase transition. Considering critical points at \alpha_1\approx 0.4 and \alpha_2\approx 2.5, we give an explanation of the freezing of \alpha_s.Comment: 15 pages, 5 figures, Presented at the 12th Lomonosov Conference on Elementary Particle Physics, Moscow State University, Moscow, 25-31 August, 200

    The Fundamental-Weak Scale Hierarchy in the Standard Model

    Full text link
    The multiple point principle, according to which several vacuum states with the same energy density exist, is put forward as a fine-tuning mechanism predicting the ratio between the fundamental and electroweak scales in the Standard Model (SM). It is shown that this ratio is exponentially huge: ∼e40\sim e^{40}. Using renormalisation group equations for the SM, we obtain the effective potential in the 2-loop approximation and investigate the existence of its postulated second minimum at the fundamental scale. The investigation of the evolution of the top quark Yukawa coupling constant in the 2-loop approximation shows that, with initial values of the top Yukawa coupling in the interval h(Mt)=0.95±0.03h(M_t)=0.95\pm 0.03 (here MtM_t is the top quark pole mass), a second minimum of the SM effective potential can exist in the region ϕmin2≈1016−1022\phi_{min2}\approx 10^{16}-10^{22} GeV. A prediction is made of the existence of a new bound state of 6 top quarks and 6 anti-top quarks, formed due to Higgs boson exchanges between pairs of quarks/anti-quarks. This bound state is supposed to condense in a new phase of the SM vacuum. This gives rise to the possibility of having a phase transition between vacua with and without such a condensate. The existence of three vacuum states (new, electroweak and fundamental) solves the hierarchy problem in the SM.Comment: 30 pages, 7 figures; to be published in Phys. Atom. Nuc
    • …
    corecore