4,824 research outputs found

    Reconciliation of CDM abundance and μeγ\mu\to e\gamma in a radiative seesaw model

    Full text link
    We reexamine relic abundance of a singlet fermion as a CDM candidate, which contributes to the neutrino mass generation through radiative seesaw mechanism. We search solutions for Yukawa couplings and the mass spectrum of relevant fields to explain neutrino oscillation data. For such solutions, we show that an abundance of a lightest singlet fermion can be consistent with WMAP data without conflicting with both bounds of μeγ\mu\to e\gamma and τμγ\tau\to \mu\gamma. This reconciliation does not need any modification of the original radiative seesaw model other than by specifying flavor structure of Yukawa couplings and taking account of coannihilation effects.Comment: 16 pages, 2 figures, accepted version for publication

    Neutrino masses and μ\mu terms in a supersymmetric extra U(1) model

    Full text link
    We propose a supersymmetric extra U(1) model, which can generate small neutrino masses and necessary μ\mu terms, simultaneously. Fields including quarks and leptons are embedded in three 27{\bf 27}s of E6E_6 in a different way among generations. The model has an extra U(1) gauge symmetry at TeV regions, which has discriminating features from other models studied previously. Since a neutrino mass matrix induced in the model has a constrained texture with limited parameters, it can give a prediction. If we impose neutrino oscillation data to fix those parameters, a value of sinθ13\sin\theta_{13} can be determined. We also discuss several phenomenological features which are discriminated from the ones of the MSSM.Comment: 27 pages, 2 figures, final version for publicatio

    The effect of grades on the preference effect : Grading Reduces Consideration of Disconfirming Evidence

    Get PDF
    The tendency to look for evidence that supports, rather than questions, one's viewpoint (preference effect) is a pervasive phenomenon. Although one important goal of education is developing critical thinking, the widespread practice of grading might discourage students in appreciating disconfirming evidence. We hypothesized that individual grading increases the preference effect. In Experiment 1, participants who expected to be graded exhibited a higher preference effect compared to participants who expected their work to be merely visible. Experiment 2 replicated this effect and further showed that grading increased participants' perception of a competitive social comparison. Implications for educational policies are discussed.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    A novel metric for coronal MHD models

    Get PDF
    [1] In the interest of quantitatively assessing the capabilities of coronal MHD models, we have developed a metric that compares the structures of the white light corona observed with SOHO LASCO C2 to model predictions. The MAS model is compared to C2 observations from two Carrington rotations during solar cycle 23, CR1913 and CR1984, which were near the minimum and maximum of solar activity, respectively, for three radial heights, 2.5 R⊙, 3.0 R⊙, and 4.5 R⊙. In addition to simulated polarization brightness images, we create a synthetic image based on the field topology along the line of sight in the model. This open-closed brightness is also compared to LASCO C2 after renormalization. In general, the model\u27s magnetic structure is a closer match to observed coronal structures than the model\u27s density structure. This is expected from the simplified energy equations used in current global corona MHD models

    Open and / or laparoscopic surgical treatment of liver hydatic cysts

    Get PDF
    Hydatid disease is a severe parasitic disease with a widely ranging distribution. In the human being the liver is the most frequent organ affected. 1 The treatment should be individualized to the morphology, size, number and location of the cysts, that is why a variety of surgical operations have been advocated from complete resection like total pericystectomy or partial hepatectomy to laparoscopy to a minimally invasive procedures like percutaneous aspiration of cysts to conservative drug therapy. 3-4 This study compares laparoscopic versus open management of the hydatid cyst of liver the surgical approach to liver echinococcosis is still a controversial issue and shows our results of surgical treatment of liver hydatid cysts during a 3-years period

    Uni-directional transport properties of a serpent billiard

    Full text link
    We present a dynamical analysis of a classical billiard chain -- a channel with parallel semi-circular walls, which can serve as a model for a bended optical fiber. An interesting feature of this model is the fact that the phase space separates into two disjoint invariant components corresponding to the left and right uni-directional motions. Dynamics is decomposed into the jump map -- a Poincare map between the two ends of a basic cell, and the time function -- traveling time across a basic cell of a point on a surface of section. The jump map has a mixed phase space where the relative sizes of the regular and chaotic components depend on the width of the channel. For a suitable value of this parameter we can have almost fully chaotic phase space. We have studied numerically the Lyapunov exponents, time auto-correlation functions and diffusion of particles along the chain. As a result of a singularity of the time function we obtain marginally-normal diffusion after we subtract the average drift. The last result is also supported by some analytical arguments.Comment: 15 pages, 9 figure (19 .(e)ps files
    corecore