1,045 research outputs found

    Growth of Hg1−xCdxTe single crystals by travelling heater method under accelerated crucible rotation conditions

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    The accelerated crucible rotation technique (ACRT) has been applied to the THM growth of Hg1−xCdxTe crystals to grow the crystals at a higher rate. These higher growth rates, which should be achieved by extending the regions of conventional stirring towards the interfaces, have been used in an attempt to explain the results in terms of simple constitutional supercooling arguments. Some different ACRT cycles which fulfil simple hydrodynamic and geometric criteria have been studied. The grown crystals were investigated with respect to their metallurgical homogeneity and their structural perfection. These properties have not been degraded by increasing the growth rate from 1.5 to 8.5 mm per day

    Gauge Consistent Wilson Renormalization Group II: Non-Abelian Case

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    We give a wilsonian formulation of non-abelian gauge theories explicitly consistent with axial gauge Ward identitities. The issues of unitarity and dependence on the quantization direction are carefully investigated. A wilsonian computation of the one-loop QCD beta function is performed.Comment: 34 pages, 1 eps figure, latex2e. Minor changes, version to appear in Int. J. Mod. Phy

    The Fermion Self-Energy during Inflation

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    We compute the one loop fermion self-energy for massless Dirac + Einstein in the presence of a locally de Sitter background. We employ dimensional regularization and obtain a fully renormalized result by absorbing all divergences with BPHZ counterterms. An interesting technical aspect of this computation is the need for a noninvariant counterterm owing to the breaking of de Sitter invariance by our gauge condition. Our result can be used in the quantum-corrected Dirac equation to search for inflation-enhanced quantum effects from gravitons, analogous to those which have been found for massless, minimally coupled scalars.Comment: 63 pages, 3 figures (uses axodraw.sty), LaTeX 2epsilon. Revised version (to appear in Classical and Quantum Gravity) corrects some typoes and contains some new reference

    Supersymmetric Yang-Mills-Chern-Simons theory

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    We prove that three-dimensional N=1 supersymmetric Yang-Mills-Chern-Simons theory is finite to all loops. This leaves open the possibility that different regularization methods give different finite effective actions. We show that for this model dimensional regularization and regularization by dimensional reduction yield the same effective action.Comment: 6 pages, 1 figure, latex, espcrc2. Contribution to the Proceedings of the 30th Ahrenshoop Symposium on the Theory of Elementary Particles, edited by D. Lust, H.-J. Otto and G. Weigt, to appear in Nuclear Physics B, Proceedings Supplemen

    Decoupling of the ϵ\epsilon-scalar mass in softly broken supersymmetry

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    It has been shown recently that the introduction of an unphysical ϵ\epsilon-scalar mass m~\tilde{m} is necessary for the proper renormalization of softly broken supersymmetric theories by dimensional reduction (\drbar). In these theories, both the two-loop β\beta-functions of the scalar masses and their one-loop finite corrections depend on m~2\tilde{m}^2. We find, however, that the dependence on m~2\tilde{m}^2 can be completely removed by slightly modifying the \drbar renormalization scheme. We also show that previous \drbar calculations of one-loop corrections in supersymmetry which ignored the m~2\tilde{m}^2 contribution correspond to using this modified scheme.Comment: 7 pages, LTH-336, NUB-3094-94TH, KEK-TH-40

    Regularization Dependence of Running Couplings in Softly Broken Supersymmetry

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    We discuss the dependence of running couplings on the choice of regularization method in a general softly-broken N=1 supersymmetric theory. Regularization by dimensional reduction respects supersymmetry, but standard dimensional regularization does not. We find expressions for the differences between running couplings in the modified minimal subtraction schemes of these two regularization methods, to one loop order. We also find the two-loop renormalization group equations for gaugino masses in both schemes, and discuss the application of these results to the Minimal Supersymmetric Standard Model.Comment: 11 pages. v2: Signs of equations (1.2) and (4.2) are fixe

    Two-loop renormalization of gaugino masses in general supersymmetric gauge models

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    We calculate the two-loop renormalization group equations for the running gaugino masses in general SUSY gauge models, improving our previous result. We also study its consequence to the unification of the gaugino masses in the SUSY SU(5) model. The two-loop correction to the one-loop relation mi(μ)αi(μ)m_i(\mu)\propto\alpha_i(\mu) is found to be of the order of a few \%.Comment: 8 pages + 1 figure (omitted),KEK-TH-371 / UT-65

    Trace Anomaly and Backreaction of the Dynamical Casimir Effect

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    The Casimir energy for massless scalar field which satisfies priodic boundary conditions in two-dimensional domain wall background is calculated by making use of general properties of renormalized stress-tensor. The line element of domain wall is time dependent, the trace anomaly which is the nonvanishing TμμT^{\mu}_{\mu} for a conformally invariant field after renormalization, represent the back reaction of the dynamical Casimir effect.Comment: 8 pages, no figures, typos corrected, discussion added, has been accepted for the publication in GR

    Relation between the pole and the minimally subtracted mass in dimensional regularization and dimensional reduction to three-loop order

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    We compute the relation between the pole quark mass and the minimally subtracted quark mass in the framework of QCD applying dimensional reduction as a regularization scheme. Special emphasis is put on the evanescent couplings and the renormalization of the epsilon-scalar mass. As a by-product we obtain the three-loop on-shell renormalization constants Zm(OS) and Z2(OS) in dimensional regularization and thus provide the first independent check of the analytical results computed several years ago.Comment: 22 page

    General structure of the graviton self-energy

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    The graviton self-energy at finite temperature depends on fourteen structure functions. We show that, in the absence of tadpoles, the gauge invariance of the effective action imposes three non-linear relations among these functions. The consequences of such constraints, which must be satisfied by the thermal graviton self-energy to all orders, are explicitly verified in general linear gauges to one loop order.Comment: 4 pages, minor corrections of typo
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