8,857 research outputs found

    Breaking the electroweak symmetry and supersymmetry by a compact extra dimension

    Full text link
    We revisit in some more detail a recent specific proposal for the breaking of the electroweak symmetry and of supersymmetry by a compact extra dimension. Possible mass terms for the Higgs and the matter hypermultiplets are considered and their effects on the spectrum analyzed. Previous conclusions are reinforced and put on firmer ground.Comment: 25 pages, LaTeX, 9 eps figure

    Oceanographic applications of the Kalman filter

    Get PDF
    The Kalman filter is a data-processing algorithm with a distinguished history in systems theory. Its application to oceanographic problems is in the embryo stage. The behavior of the filter is demonstrated in the context of an internal equatorial Rossby wave propagation problem

    Utilization requirements. A southern California Gas Company project SAGE report: Utilization requirements

    Get PDF
    Utilization requirements are given and comparisons made of two phase III SAGE (solar assisted gas energy) installations in California: (1) a retrofit installation in an existing apartment building in El Toro, and (2) an installation in a new apartment building in Upland. Such testing in the field revealed the requirements to be met if SAGE-type installations are to become commercially practical on a widespread basis in electric and gas energy usage

    Minimal Flavour Violation with hierarchical squark masses

    Full text link
    In a supersymmetric model with hierarchical squark masses we analyze a pattern of flavour symmetry breaking centered on the special role of the top Yukawa coupling and, by extension, of the full Yukawa couplings for the up-type quarks. For sufficiently heavy squarks of the first and second generation this leads to effective Minimal Flavour Violation of the Flavour Changing Neutral Current amplitudes. For this to happen we determine the bounds on the masses of the heavy squarks with QCD corrections taken into account, properly including previously neglected effects. We believe that the view presented in this paper altogether strengthens the case for hierarchical sfermions.Comment: 13 pages, 1 figure. v2: an equation correcte

    The Hosotani Mechanism in Bulk Gauge Theories with an Orbifold Extra Space S^1/Z_2

    Get PDF
    We pursue the possibility of the scenario in which the Higgs field is identified with the extra-space component of a bulk gauge field. The space-time we take is M4^{4} \otimes S1^1/Z2_2. We show that a non-trivial Z2_2-parity assignment allows some of the extra-space component to have radiatively induced VEV, which strongly modifies the mass spectrum and gauge symmetry of the theory, realized by oribifolding. In particular we investigate the dynamical mass generation of zero-mode fermion and spontaneous gauge symmetry breaking due to the VEV. The gauge theories we adopt are a prototype model SU(2) and SU(3) model, of special interest as the realistic minimal scheme to incorporate the standard model SU(2) ×\times U(1).Comment: 16 pages 3 figure

    Less Minimal Flavour Violation

    Full text link
    We consider the approximate U(2)^3 flavour symmetry exhibited by the quark sector of the Standard Model and all its possible breaking terms appearing in the quark Yukawa couplings. Taking an Effective Field Theory point of view, we determine the current bounds on these parameters, assumed to control the breaking of flavour in a generic extension of the Standard Model at a reference scale Lambda. In particular, a significant bound from epsilon'/epsilon is derived, which is relevant to Minimal Flavour Violation as well. In the up-quark sector, the recently observed CP violation in D -> pi+ pi-, K+ K- decays might be accounted for in this generic framework, consistently with any other constraint.Comment: 15 pages, 1 figur

    Charm and Bottom Quark Masses from Perturbative QCD

    Get PDF
    Using a new result for the first moment of the hadronic production cross section at order O(αs3){\cal O}(\alpha_s^3), and new data on the J/ψJ/\psi and ψ\psi' resonances for the charm quark, we determine the \msb masses of the charm and bottom quarks to be mˉc(mˉc)=1.295±0.015\bar{m}_c(\bar{m}_c) = 1.295 \pm 0.015 GeV and mˉb(mˉb)=4.205±0.058\bar{m}_b(\bar{m}_b) = 4.205 \pm 0.058 GeV. We assume that the continuum contribution to the sum rules is adequately described by pQCD. While we observe a large reduction of the perturbative error, the shifts induced by the theoretical input are very small. The main change in the central value of mcm_c is related to the experimental data. On the other hand, the value of mbm_b is not changed by our calculation to the assumed precision.Comment: 5 pages, 2 figures, final version as publishe

    The Neron-Severi group of a proper seminormal complex variety

    Full text link
    We prove a Lefschetz (1,1)-Theorem for proper seminormal varieties over the complex numbers. The proof is a non-trivial geometric argument applied to the isogeny class of the Lefschetz 1-motive associated to the mixed Hodge structure on H^2.Comment: 16 pages; Mathematische Zeitschrift (2008

    Logarithmic SUSY electroweak effects on four-fermion processes at TeV energies

    Full text link
    We compute the MSSM one-loop contributions to the asymptotic energy behaviour of fermion-antifermion pair production at future lepton-antilepton colliders. Besides the conventional logarithms of Renormalization Group origin, extra SUSY linear logarithmic terms appear of "Sudakov-type". In the TeV range their overall effect on a variety of observables can be quite relevant and drastically different from that obtained in the SM case.Comment: 19 pages and 14 figures, corrected version. e-mail: [email protected]

    The Higgs boson from an extended symmetry

    Full text link
    The variety of ideas put forward in the context of a "composite" picture for the Higgs boson calls for a simple and effective description of the related phenomenology. Such a description is given here by means of a "minimal" model and is explicitly applied to the example of a Higgs-top sector from an SO(5) symmetry. We discuss the spectrum, the ElectroWeak Precision Tests, B-physics and naturalness. We show the difficulty to comply with the different constraints. The extended gauge sector relative to the standard SU(2)xU(1), if there is any, has little or no impact on these considerations. We also discuss the relation of the "minimal" model with its "little Higgs" or "holographic" extensions based on the same symmetry.Comment: 22 pp; v3: Small corrections, version to be published in Phys. Rev.
    corecore