853 research outputs found

    Brave Forms of Mentoring Supported by Technology in Teacher Education

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    Indexación: Web of ScienceQuality education is undoubtedly a global concern, tied closely to preoccupations with economic and social development. Increasingly, the adoption and effective use of current technology tools are being recognized as visible signs of that quality. Scholars are providing increasing evidence of the kinds of empowered teacher identities that will adopt the effective use of technology tools in teaching. Less is being discussed about how technology can support the processes needed to mediate such identities. The context of Teacher Education is a strategic place to begin to initiate such processes. Our aim in this article is twofold: 1) to describe two recent examples of innovative, technology - supported mentoring processes that were conducted in the context of an EFL Teacher Education program in Chile; 2) to revisit the findings of these studies in light of new evidence from participants who have moved on in their careers. This evidence is viewed in the framework of recent scholarship on the responsibilities that Teacher Education plays in their development. The first 16-month study examined the influences of a guided reading program involving e-readers on the identities and literacy skills of pre-service teachers. The second was a student-conceived study. That inquiry sought to determine the influence of upper year students' peer mentoring, made available partly through a social media site (SMS), on the identities and investment in learning of 12 firs-year students in the pedagogy program. The initial evidence from ethnographic tools used in both studies indicated that the participants were struggling with confidence and doubting themselves as knowledgeable, effective future teachers - not predictive of a potential for quality teaching. Positive signs at the end of both studies and more recent reports from participants suggest that the mentoring had longitudinal benefits for some, although not uniformly. The potential of apprenticeship and mentoring in a technology-supported environment requires rethinking Teacher Education mandates if we are to empower emerging teachers to be quality teachers.http://www.ejel.org/issue/download.html?idArticle=48

    SO(10) SUSY GUT for Fermion Masses : Lepton Flavor and CP Violation

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    We discuss the results of a global χ2\chi^2 analysis of a simple SO(10) SUSY GUT with D3D_3 family symmetry and low energy R parity. The model describes fermion mass matrices with 14 parameters and gives excellent fits to 20 observable masses and mixing angles in both quark and lepton sectors, giving 6 predictions. Bi-large neutrino mixing is obtained with hierarchical quark and lepton Yukawa matrices; thus avoiding the possibility of large lepton flavor violation. The model naturally predicts small 1-3 neutrino mixing, with sinθ130.050.06\sin \theta_{13} \simeq 0.05 - 0.06. In this paper we evaluate the predictions for the lepton flavor violating processes, μeγ\mu \to e \gamma, τμγ\tau \to \mu \gamma and τeγ\tau \to e \gamma and also the electric dipole moment of the electron, ded_e, muon and tau, assuming universal squark and slepton masses, m16m_{16}, and a universal soft SUSY breaking A parameter, A0A_0, at the GUT scale. We find Br(μeγ)Br(\mu \to e \gamma) is naturally below present bounds, but may be observable by MEG. Similarly, ded_e is below present bounds; but is within the range of future experiments. We also give predictions for the light Higgs mass (using FeynHiggs). We find an upper bound given by mh127m_h \leq 127 GeV, with an estimated ±3\pm 3 GeV theoretical uncertainty. Finally we present predictions for SUSY particle masses in the favored region of parameter space.Comment: 25 pages, 18 figures, several typos in captions of tables 2 and 3 corrected, acknowledgments adde

    A solution to the mu problem in the presence of a heavy gluino LSP

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    In this paper we present a solution to the μ\mu problem in an SO(10) supersymmetric grand unified model with gauge mediated and D-term supersymmetry breaking. A Peccei-Quinn symmetry is broken at the messenger scale M1012M\sim 10^{12} GeV and enables the generation of the μ\mu term. The boundary conditions defined at MM lead to a phenomenologically acceptable version of the minimal supersymmetric standard model with novel particle phenomenology. Either the gluino or the gravitino is the lightest supersymmetric particle (LSP). If the gravitino is the LSP, then the gluino is the next-to-LSP (NLSP) with a lifetime on the order of one month or longer. In either case this heavy gluino, with mass in the range 25 - 35 GeV, can be treated as a stable particle with respect to experiments at high energy accelerators. Given the extensive phenomenological constraints we show that the model can only survive in a narrow region of parameter space resulting in a light neutral Higgs with mass 8691\sim 86 - 91 GeV and tanβ914\tan\beta \sim 9 - 14. In addition the lightest stop and neutralino have mass 100122\sim 100 - 122 GeV and 5072\sim 50 - 72 GeV, respectively. Thus the model will soon be tested. Finally, the invisible axion resulting from PQ symmetry breaking is a cold dark matter candidate.Comment: 30 pages, 9 figure

    Can multi-TeV (top and other) squarks be natural in gauge mediation?

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    We investigate whether multi-TeV (1-3 TeV) squarks can be natural in models of gauge mediated SUSY breaking. The idea is that for some boundary condition of the scalar (Higgs and stop) masses, the Higgs (mass)2^2, evaluated at the renormalization scale O(100)\sim O(100) GeV, is not very sensitive to (boundary values of) the scalar masses (this has been called ``focussing'' in recent literature). Then, the stop masses can be multi-TeV without leading to fine-tuning in electroweak symmetry breaking. {\em Minimal} gauge mediation does {\em not} lead to this focussing (for all values of tanβ\tan \beta and the messenger scale): the (boundary value of) the Higgs mass is too small compared to the stop masses. Also, in minimal gauge mediation, the gaugino masses are of the same order as the scalar masses so that multi-TeV scalars implies multi-TeV gauginos (especially gluino) leading to fine-tuning. We discuss ideas to {\em increase} the Higgs mass relative to the stop masses (so that focussing can be achieved) and also to {\em suppress} gaugino masses relative to scalar masses (or to modify the gaugino mass relations) in {\em non-minimal} models of gauge mediation -- then multi-TeV (top and other) squarks can be natural. Specific models of gauge mediation which incorporate these ideas and thus have squarks (and in some cases, the gluino) heavier than a TeV without resulting in fine-tuning are also studied and their collider signals are contrasted with those of other models which have multi-TeV squarks.Comment: LaTeX, 29 pages, 9 eps figures. Replacing an earlier version. In version 3, some references and a minor comment have been added and typos have been correcte

    String-derived D4 flavor symmetry and phenomenological implications

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    In this paper we show how some flavor symmetries may be derived from the heterotic string, when compactified on a 6D orbifold. In the body of the paper we focus on the D4D_4 family symmetry, recently obtained in Z3×Z2Z_3 \times Z_2 orbifold constructions. We show how this flavor symmetry constrains fermion masses, as well as the soft SUSY breaking mass terms. Flavor symmetry breaking can generate the hierarchy of fermion masses and at the same time the flavor symmetry suppresses large flavor changing neutral current processes.Comment: 17 pages, no figur

    Patterns of Dynamical Gauge Symmetry Breaking

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    We construct and analyze theories with a gauge symmetry in the ultraviolet of the form GGbG \otimes G_b, in which the vectorial, asymptotically free GbG_b gauge interaction becomes strongly coupled at a scale where the GG interaction is weakly coupled and produces bilinear fermion condensates that dynamically break the GG symmetry. Comparisons are given between Higgs and dynamical symmetry breaking mechanisms for various models.Comment: 14 pages, late

    Color Superconductivity from Supersymmetry

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    A supersymmetric composite model of color superconductivity is proposed. Quarks and diquarks are dynamically generated as composite fields by a newly introduced strong gauge dynamics. It is shown that the condensation of the scalar component of the diquark supermultiplet occurs when the chemical potential becomes larger than some critical value. We believe that the model well captures aspects of the diquark condensate behavior and helps our understanding of the diquark dynamics in real QCD. The results obtained here might be useful when we consider a theory composed of quarks and diquarks.Comment: 4 pages, 2 figures, An error in Eq.(10) correcte

    Trouble for MAC

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    We show that the next-to-leading corrections to the kernel of the gap equation can be large and of opposite sign to the lowest order kernel, in the presence of a gauge boson mass. This calls into question the reliability of the Most Attractive Channel hypothesis.Comment: 8 pages, 1 figure, LaTe

    Probing the nature of the seesaw in renormalizable SO(10)

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    We study the nature of the see-saw mechanism in the context of renormalizable SO(10) with Higgs fields in the 10-plets and 126-plet representations, paying special attention to the supersymmetric case. We discuss analytically the situation for the second and third generations of fermions ignoring any CP violating phase. It is shown that b-tau unification and large atmospheric mixing angle strongly disfavor the dominance of the type I see-saw.Comment: 12 page

    Heterotic Cosmic Strings

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    We show that all three conditions for the cosmological relevance of heterotic cosmic strings, the right tension, stability and a production mechanism at the end of inflation, can be met in the strongly coupled M-theory regime. Whereas cosmic strings generated from weakly coupled heterotic strings have the well known problems posed by Witten in 1985, we show that strings arising from M5-branes wrapped around 4-cycles (divisors) of a Calabi-Yau in heterotic M-theory compactifications, solve these problems in an elegant fashion.Comment: 25 pages, v2: section and references adde
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