2,127 research outputs found

    Revisiting Critical Vortices in Three-Dimensional SQED

    Full text link
    We consider renormalization of the central charge and the mass of the N=2{\cal N}=2 supersymmetric Abelian vortices in 2+1 dimensions. We obtain N=2{\cal N}=2 supersymmetric theory in 2+1 dimensions by dimensionally reducing the N=1{\cal N}=1 SQED in 3+1 dimensions with two chiral fields carrying opposite charges. Then we introduce a mass for one of the matter multiplets without breaking N=2 supersymmetry. This massive multiplet is viewed as a regulator in the large mass limit. We show that the mass and the central charge of the vortex get the same nonvanishing quantum corrections, which preserves BPS saturation at the quantum level. Comparison with the operator form of the central extension exhibits fractionalization of a global U(1) charge; it becomes 1/2 for the minimal vortex. The very fact of the mass and charge renormalization is due to a "reflection" of an unbalanced number of the fermion and boson zero modes on the vortex in the regulator sector.Comment: 24 pages, 2 figures Minor modifications, reference adde

    Shift in the LHC Higgs diphoton mass peak from interference with background

    Full text link
    The Higgs diphoton amplitude from gluon fusion at the LHC interferes with the continuum background induced by quark loops. I investigate the effect of this interference on the position of the diphoton invariant mass peak used to help determine the Higgs mass. At leading order, the interference shifts the peak towards lower mass by an amount of order 150 MeV or more, with the precise value dependent on the methods used to analyze and fit the data.Comment: 10 pages. v2: comments on scale variation added, reference adde

    Indirect Detection of Little Higgs Dark Matter

    Get PDF
    Little Higgs models with T parity contain an attractive dark matter candidate, the heavy photon. We compute the cross section of the heavy photon annihilation into Z-photon pairs, which turns out to be substantially higher than the previously computed cross section for the two photon final state. Unfortunately, even with this enhancement, the monochromatic photon flux from galactic heavy photon annihilation is unlikely to be detectable by GLAST or the currently operating atmospheric Cerenkov telescopes. We also compute the flux of high-energy neutrinos from the annihilation of the heavy photons captured by the Sun and the Earth. The maximum flux of upward-going muons due to such neutrinos is about 1 yr^{-1}km^{-2}.Comment: 13 pages, 3 figure

    Large-N Solution of the Heterotic CP(N-1) Model with Twisted Masses

    Full text link
    We address a number of unanswered questions in the N=(0,2)-deformed CP(N-1) model with twisted masses. In particular, we complete the program of solving CP(N-1) model with twisted masses in the large-N limit. In hep-th/0512153 nonsupersymmetric version of the model with the Z_N symmetric twisted masses was analyzed in the framework of Witten's method. In arXiv:0803.0698 this analysis was extended: the large-N solution of the heterotic N=(0,2) CP(N-1) model with no twisted masses was found. Here we solve this model with the twisted masses switched on. Dynamical scenarios at large and small m are studied (m is the twisted mass scale). We found three distinct phases and two phase transitions on the m plane. Two phases with the spontaneously broken Z_N-symmetry are separated by a phase with unbroken Z_N. This latter phase is characterized by a unique vacuum and confinement of all U(1) charged fields ("quarks"). In the broken phases (one of them is at strong coupling) there are N degenerate vacua and no confinement, similarly to the situation in the N=(2,2) model. Supersymmetry is spontaneously broken everywhere except a circle |m|=\Lambda in the Z_N-unbroken phase. Related issues are considered. In particular, we discuss the mirror representation for the heterotic model in a certain limiting case.Comment: 69 pages, 14 figures; typos corrected, final version to appear in PRD; v Jan. 2014 Erratum added on p. 50, two references added and two references update

    Dynamical GUT breaking and mu-term driven supersymmetry breaking

    Get PDF
    Models for dynamical breaking of supersymmetric grand unified theories are presented. The doublet-triplet splitting problem is absent since the Higgs doublet superfields can be identified with the massless mesons of the strong gauge group whereas there are no massless states corresponding to the colored Higgs fields. Various strong gauge groups SU(Nc), Sp(Nc) and SO(Nc) are examined. In a model with SO(9) strong gauge group, adding the mu-term for the Higgs fields triggers to break supersymmetry in a meta-stable vacuum. The pattern of the supersymmetry breaking parameters is predicted to be the gauge-mediation type with modifications in the Higgs sector.Comment: 23 pages, 1 figure; version to appear in PR

    Are There Hints of Light Stops in Recent Higgs Search Results?

    Full text link
    The recent discovery at the LHC by the CMS and ATLAS collaborations of the Higgs boson presents, at long last, direct probes of the mechanism for electroweak symmetry breaking. While it is clear from the observations that the new particle plays some role in this process, it is not yet apparent whether the couplings and widths of the observed particle match those predicted by the Standard Model. In this paper, we perform a global fit of the Higgs results from the LHC and Tevatron. While these results could be subject to as-yet-unknown systematics, we find that the data are significantly better fit by a Higgs with a suppressed width to gluon-gluon and an enhanced width to gamma gamma, relative to the predictions of the Standard Model. After considering a variety of new physics scenarios which could potenially modify these widths, we find that the most promising possibility is the addition of a new colored, charged particle, with a large coupling to the Higgs. Of particular interest is a light, and highly mixed, stop, which we show can provide the required alterations to the combination of gg and gamma gamma widths.Comment: 6 pages, 5 figure

    Direct Mediation of Meta-Stable Supersymmetry Breaking

    Get PDF
    The supersymmetric SU(Nc) Yang-Mills theory coupled to Nf matter fields in the fundamental representation has meta-stable vacua with broken supersymmetry when Nc < Nf < 3/2 Nc. By gauging the flavor symmetry, this model can be coupled directly to the standard model. We show that it is possible to make a slight deformation to the model so that gaugino masses are generated and the Landau pole problem can be avoided. The deformed model has simple realizations on intersecting branes in string theory, where various features of the meta-stable vacua are encoded geometrically as brane configurations.Comment: 22 pages, 4 figures, a reference added, version to appear in PR
    corecore