14,980 research outputs found

    Production of (τ+τ)b(\tau^+\tau^-)_b in electron positron collisions

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    (τ+τ)b(\tau^+\tau^-)_b is an atom of simple hydrogenlike structure similar to positronium (e+e)b(e^+e^-)_b and (μ+μ)b(\mu^+\mu^-)_b. In this paper energy levels and decay widths of different decay channels of (τ+τ)b(\tau^+\tau^-)_b are given. Cross section of production of this atomic system in e+ee^+e^- annihilation taking into account radiative corrections is calculated. According to our estimates 886 (τ+τ)b(\tau^+\tau^-)_b atoms may be produced at BEPCII and 29 (τ+τ)b(\tau^+\tau^-)_b atoms are produced at VEPP-4M under the present experimental conditions.Comment: 5 pages, submitted to Int. Jour. Mod. Phys.

    Gauge Transformations, BRST Cohomology and Wigner's Little Group

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    We discuss the (dual-)gauge transformations and BRST cohomology for the two (1 + 1)-dimensional (2D) free Abelian one-form and four (3 + 1)-dimensional (4D) free Abelian 2-form gauge theories by exploiting the (co-)BRST symmetries (and their corresponding generators) for the Lagrangian densities of these theories. For the 4D free 2-form gauge theory, we show that the changes on the antisymmetric polarization tensor e^{\mu\nu} (k) due to (i) the (dual-)gauge transformations corresponding to the internal symmetry group, and (ii) the translation subgroup T(2) of the Wigner's little group, are connected with each-other for the specific relationships among the parameters of these transformation groups. In the language of BRST cohomology defined w.r.t. the conserved and nilpotent (co-)BRST charges, the (dual-)gauge transformed states turn out to be the sum of the original state and the (co-)BRST exact states. We comment on (i) the quasi-topological nature of the 4D free 2-form gauge theory from the degrees of freedom count on e^{\mu\nu} (k), and (ii) the Wigner's little group and the BRST cohomology for the 2D one-form gauge theory {\it vis-{\`a}-vis} our analysis for the 4D 2-form gauge theory.Comment: LaTeX file, 29 pages, misprints in (3.7), (3.8), (3.9), (3.13) and (4.14)corrected and communicated to IJMPA as ``Erratum'

    Geometrical Aspects Of BRST Cohomology In Augmented Superfield Formalism

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    In the framework of augmented superfield approach, we provide the geometrical origin and interpretation for the nilpotent (anti-)BRST charges, (anti-)co-BRST charges and a non-nilpotent bosonic charge. Together, these local and conserved charges turn out to be responsible for a clear and cogent definition of the Hodge decomposition theorem in the quantum Hilbert space of states. The above charges owe their origin to the de Rham cohomological operators of differential geometry which are found to be at the heart of some of the key concepts associated with the interacting gauge theories. For our present review, we choose the two (1+1)(1 + 1)-dimensional (2D) quantum electrodynamics (QED) as a prototype field theoretical model to derive all the nilpotent symmetries for all the fields present in this interacting gauge theory in the framework of augmented superfield formulation and show that this theory is a {\it unique} example of an interacting gauge theory which provides a tractable field theoretical model for the Hodge theory.Comment: LaTeX file, 25 pages, Ref. [49] updated, correct page numbers of the Journal are give

    Superfield Approach to (Non-)local Symmetries for One-Form Abelian Gauge Theory

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    We exploit the geometrical superfield formalism to derive the local, covariant and continuous Becchi-Rouet-Stora-Tyutin (BRST) symmetry transformations and the non-local, non-covariant and continuous dual-BRST symmetry transformations for the free Abelian one-form gauge theory in four (3+1)(3 + 1)-dimensions (4D) of spacetime. Our discussion is carried out in the framework of BRST invariant Lagrangian density for the above 4D theory in the Feynman gauge. The geometrical origin and interpretation for the (dual-)BRST charges (and the transformations they generate) are provided in the language of translations of some superfields along the Grassmannian directions of the six (4+2) 4 + 2)-dimensional supermanifold parametrized by the four spacetime and two Grassmannian variables.Comment: LaTeX file, 23 page

    Green construction in India: gaining a deeper understanding

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    A workshop on green construction was organized in New Delhi in July 2008 by Jamia Millia University, India and University of Salford, U.K., aiming to increase 'green' practices that are environmentally friendly and energy efficient. The workshop included participants from regulatory bodies, public and private construction companies and researchers. The object of the workshop was to provide an opportunity to capture issues, challenges and research issues in green practices throughout the supply chain in the construction sector in India. The methodology constituted a survey that was provided to all participants, where eight questions were composed by the facilitators. The participants were asked about their views on voluntary and compulsory ways of assessment and audit of green implementation in India. The findings of the workshop featured major challenges, drivers, initiatives, and the ways of effective implementation as well as enforcement on the discussed topic

    Елементи екологічної освіти в процесі вивчення фізики

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    У статті розглянуто актуальне питання використання екологічних елементів на уроках фізики. Проаналізовано переваги їх використання у навчальному процесі. Актуальність матеріалу, викладеного у статті, обумовлена потребами у застосуванні екологічних знань для підвищення рівня засвоєння нового матеріалу з фізики.The artikle considers the use of relevant environmental elements on the physical lessons. The advantages of using them in the classroom. Relevance of material presented in the article by the need to apply ecological knowledge to improve the assimilation of new material in physics

    Nilpotent Symmetries For Matter Fields In Non-Abelian Gauge Theory: Augmented Superfield Formalism

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    In the framework of superfield approach to Becchi-Rouet-Stora-Tyutin (BRST) formalism, the derivation of the (anti-)BRST nilpotent symmetries for the matter fields, present in any arbitrary interacting gauge theory, has been a long-standing problem. In our present investigation, the local, covariant, continuous and off-shell nilpotent (anti-)BRST symmetry transformations for the Dirac fields (ψ,ψˉ)(\psi, \bar\psi) are derived in the framework of the augmented superfield formulation where the four (3+1)(3 + 1)-dimensional (4D) interacting non-Abelian gauge theory is considered on the six (4+2)(4 + 2)-dimensional supermanifold parametrized by the four even spacetime coordinates xμx^\mu and a couple of odd elements (θ\theta and θˉ\bar\theta) of the Grassmann algebra. The requirement of the invariance of the matter (super)currents and the horizontality condition on the (super)manifolds leads to the derivation of the nilpotent symmetries for the matter fields as well as the gauge- and the (anti-)ghost fields of the theory in the general scheme of the augmented superfield formalism.Comment: LaTeX file, 16 pages, printing mistakes in the second paragraph of `Introduction' corrected, a footnote added, these modifications submitted as ``erratum'' to IJMPA in the final for
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