687 research outputs found

    Someone Like Us: Trades identities and support for work/learning

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    This paper reflects on specific findings from a 2009 study of on and off-job learning that explored apprentices’ learning experiences, formal and informal learning connections, and implications for language, literacy and numeracy in vocational learning. The study was conducted in the glazing industry in New Zealandi, and as part of that study, apprentice profiles were developed. This discussion focuses on three of those profiles and reflects on two emerging themes. The first theme is employer and apprentice perceptions of the value of apprentices coming from a ‘trades family’. The second theme is the range of inclusions and exclusions, advantages and disadvantages that apprentices experience depending on their ‘trades family’ status in both on and off-job learning. The paper then considers what kind of learning support might help integrate the different identities required within an apprenticeship

    Cultural/Community Mentoring with Maori and Pacific Electrical Apprentices

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    New Zealand government policy documents over the last decade have committed to supporting Maori and Pasifika learners, yet still today there is little real support in place for learners in apprenticeships. There is even less support in place that acknowledges the cultural dimension of learning in the workplace. This paper discusses the establishment and review of a development project which sets out to provide culturally supportive mentoring for Maori and Pasifika apprentices. The project sought to do this by engaging experienced Maori and Pasifika tradesmen who were located in the local communities of their learners

    New Higgs physics from the lattice

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    We report the first results from our comprehensive lattice tool set to explore non-perturbative aspects of Higgs physics in the Standard Model. We demonstrate in Higgs-Yukawa models that Higgs mass lower bounds and upper bounds can be determined in lattice simulations when triviality requires the necessity of a finite cutoff to maintain non-zero interactions. The vacuum instability problem is investigated and the lattice approach is compared with the traditional renormalization group procedure which sets similar goals to correlate lower and upper Higgs mass bounds with the scale of new physics. A novel feature of our lattice simulations is the use of Ginsparg-Wilson fermions to represent the effects of Top quark loops in Higgs dynamics. The need for chiral lattice fermions is discussed and the approach is extended to full Top-Higgs-QCD dynamics. We also report results from our large NFN_F analysis of Top-Higgs Yukawa models to gain analytic insight and to verify our new lattice tool set which is deployed in the simulations. The role of non-perturbative lattice studies to investigate heavy Higgs particle scenarios is illustrated in extensions of the Standard Model.Comment: 28 pages, based on contributions from K. Holland, J. Kuti, D. Nogradi, and C. Schroeder at The XXV International Symposium on Lattice Field Theory, July 30 - August 4 2007, Regensburg, German

    Chiral symmetry breaking in fundamental and sextet fermion representations of SU(3) color

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    We report new results for lattice gauge theories with twelve fermion flavors in the fundamental representation and two fermion flavors in the two-index symmetric (sextet) representation of the SU(3) color gauge group. Both models are important in searching for a viable composite Higgs mechanism in the Beyond the Standard Model (BSM) paradigm. We subject both models to opposite hypotheses inside and outside of the conformal window. In the first hypothesis we test chiral symmetry breaking (χSB\chi{\rm SB}) with its Goldstone spectrum, FπF_\pi, the χSB\chi{\rm SB} condensate, and several composite hadron states as the fermion mass is varied in a limited range with our best effort to control finite volume effects. Supporting results for χSB\chi{\rm SB} from the running coupling based on the force between static sources is also presented. In the second test for the alternate hypothesis we probe conformal behavior driven by a single anomalous mass dimension under the assumption of unbroken chiral symmetry. Our results show very low level of confidence in the conformal scenario.Comment: 14 pages, 12 figures. Based on talks presented by J.Kuti and K.Holland at the XXVIII International Symposium on Lattice Field Theory, Lattice2010, June 14-19, 2010, Villasimius, Ital

    Probing technicolor theories with staggered fermions

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    One exciting possibility of new physics beyond the Standard Model is that the fundamental Higgs sector is replaced by a strongly-interacting gauge theory, known as technicolor. A viable theory must break chiral symmetry dynamically, like in QCD, to generate Goldstone bosons which become the longitudinal components of the W and Z. By measuring the eigenvalues of the Dirac operator, one can determine if chiral symmetry is in fact spontaneously broken. We simulate SU(3) gauge theory with n_s=2 and 3 staggered flavors in the fundamental representation, corresponding to N_f=8 and 12 flavors in the continuum limit. Although our first findings show that both theories are consistent with dynamically broken chiral symmetry and QCD-like behavior, flavor breaking effects in the spectrum may require further clarifications before final conclusions can be drawn. We also compare various improved staggered actions, to suppress this potentially large flavor breaking.Comment: 7 pages, 5 figures, talk presented at The XXVI International Symposium on Lattice Field Theory, July 14 - 19, 2008, Williamsburg, Virginia, US

    Chiral symmetry breaking in nearly conformal gauge theories

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    We present new results on chiral symmetry breaking in nearly conformal gauge theories with fermions in the fundamental representation of the SU(3) color gauge group. The number of fermion flavors is varied in an extended range below the conformal window with chiral symmetry breaking (χSB\chi{\rm SB}) for all flavors between Nf=4N_f=4 and Nf=12N_f=12. To identify χSB\chi{\rm SB} we apply several methods which include, within the framework of chiral perturbation theory, the analysis of the Goldstone spectrum in the p-regime and the spectrum of the fermion Dirac operator with eigenvalue distributions of random matrix theory in the \eps-regime. Chiral condensate enhancement is observed with increasing NfN_f when the electroweak symmetry breaking scale FF is held fixed in technicolor language. Important finite-volume consistency checks from the theoretical understanding of the SU(Nf)SU(N_f) rotator spectrum of the δ\delta-regime are discussed. We also consider these gauge theories at Nf=16N_f=16 inside the conformal window. The importance of understanding finite volume, zero momentum gauge field dynamics inside the conformal window is pointed out. Staggered lattice fermions with supressed taste breaking are used throughout the simulations.Comment: 21 pages, 9 figures. Presented at the XXVII International Symposium on Lattice Field Theory, July 26-31, 2009, Peking University, Beijin

    Calculating the running coupling in strong electroweak models

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    One possibility for Beyond Standard Model physics is a new strongly-interacting gauge theory. One way to determine if a non-abelian gauge theory is QCD-like or conformal is to measure the running of the renormalized gauge coupling. We define the renormalized coupling from Wilson loop ratios, and measure these ratios via lattice simulations. We test this method in SU(3) pure gauge theory and show some first results for simulations with dynamical fermions in the fundamental representation.Comment: 7 pages, 5 figures. Presented at the XXVII International Symposium on Lattice Field Theory, July 26-31, 2009, Peking University, Beijin

    Nearly conformal electroweak sector with chiral fermions

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    SU(3) gauge theory with dynamical overlap fermions in the 2-index symmetric (sextet) representation is considered. This model may be a viable model of the electroweak symmetry breaking sector along the lines of the walking technicolor paradigm. The number of fermion species is chosen such that the theory is expected to be below the conformal window. We will discuss how the epsilon-regime and random matrix theory can be used to test whether at any given set of parameters (N_c, N_f, representation) the theory is in the conformal phase or indeed just below it. Quenched Monte Carlo results are included in the fundamental representation and also preliminary dynamical ones in the 2-index symmetric representation.Comment: 7 pages, 2 figures, talk presented at The XXVI International Symposium on Lattice Field Theory, July 14 - 19, 2008, Williamsburg, Virginia, US

    The sextet gauge model, light Higgs, and the dilaton

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    The frequently discussed strongly interacting gauge theory with a fermion flavor doublet in the two-index symmetric (sextet) representation of the SU(3) color gauge group is investigated \cite{Fodor:2012ty}. The chiral condensate and the mass spectrum are consistent with chiral symmetry breaking at vanishing fermion mass. In contrast, sextet fermion mass deformations of spectral properties are not consistent with leading conformal scaling behavior near the critical surface of a conformal theory. A recent paper \cite{DeGrand:2012yq} which could not resolve the conformal fixed point of the gauge coupling from the slowly walking scenario of a very small nearly vanishing \beta -function is not in conflict with chiral symmetry breaking reported here. A light Higgs impostor could emerge as the dilaton from spontaneous symmetry breaking of scale invariance or, without the dilaton mechanism, as a composite state.Comment: 7 pages, Proceedings of the 30th International Symposium on Lattice Field Theory, June 24 - 29, 2012, Cairns, Australi
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