14,276 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+e−e^+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.

    Cohomological aspects of Abelian gauge theory

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    We discuss some aspects of cohomological properties of a two-dimensional free Abelian gauge theory in the framework of BRST formalism. We derive the conserved and nilpotent BRST- and co-BRST charges and express the Hodge decomposition theorem in terms of these charges and a conserved bosonic charge corresponding to the Laplacian operator. It is because of the topological nature of free U(1) gauge theory that the Laplacian operator goes to zero when equations of motion are exploited. We derive two sets of topological invariants which are related to each-other by a certain kind of duality transformation and express the Lagrangian density of this theory as the sum of terms that are BRST- and co-BRST invariants. Mathematically, this theory captures together some of the key features of Witten- and Schwarz type of topological field theories.Comment: 12 pages, LaTeX, no figures, Title and text have been slightly changed, Journal reference is given and a reference has been adde

    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

    Chemotherapy-induced non-Hodgkin\u27s lymphoma in a patient with Hodgkin\u27s disease--a case report

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    Modern chemotherapy and radiation treatment of Hodgkin’s disease has resulted in overall cure rates in excess of 60%1 . However, the greatly improved survival rates have also led to increasing incidence of long-term side-effects of these treatment modalities2 . The most serious consequence is the occurrence of second cancer3 . We report a case of non-Hodgkin’s lymphoma occurring in a patient who was previously treated for Hodgkin’s disease

    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

    Constraints on the three-fluid model of curvaton decay

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    A three fluid system describing the decay of the curvaton is studied by numerical and analytical means. We place constraints on the allowed interaction strengths between the fluids and initial curvaton density by requiring that the curvaton decays before nucleosynthesis while nucleosynthesis, radiation-matter equality and decoupling occur at correct temperatures. We find that with a continuous, time-independent interaction, a small initial curvaton density is naturally preferred along with a low reheating temperature. Allowing for a time-dependent interaction, this constraint can be relaxed. In both cases, a purely adiabatic final state can be generated, but not without fine-tuning. Unlike in the two fluid system, the time-dependent interactions are found to have a small effect on the curvature perturbation itself due to the different nature of the system. The presence of non-gaussianity in the model is discussed.Comment: 9 pages, 10 figure

    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'

    DIET COMPOSITION OF ANOA (Buballus sp.) STUDIED USING DIRECT OBSERVATION AND DUNG ANALYSIS METHOD IN THEIR HABITAT

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    Anoa are fully protected under Indonesian Law since 1931 (Law of Protection of Wild Animals 1931, no 134). Increasing law enforcement regarding hunting as well as promoting awareness of the Anoas unique threatened the existence of conservation measures. The modern concept of conservation based on the sustainability utilization, and therefore the knowledge of the Anoa preference in feeding to support the sustainability conservation should be studied. In the present study, the combination of direct observation methods which was done in the Lore Lindu National Park in Toro village at District Kulawi, Central Sulawesi and the epidermal analysis method which was carried out to Anoa’s dung were aimed to identify the vegetations preferred by Anoa in their habitat. The result showed 28 species of vegetations was used as feed by Anoa on in situ area. According to its percentage, the first ten were Freycinetia insignis Blume (17%), Microlepia todayensis Christ (8.9%), Disoxylum sp (8.6%), Lasianthus clementis Merr (7.7%), Clusia sp (7.5%), Schleria sp (6%), Podocarpus imbricatus (5.4%), Smilax leucophylla (5.1%), Elastostema sp (4.2%), and Garcinia sp (3.8%), respectively. Furthermore, it can be concluded that Anoa was eat more leafs and shrubs/bushes (each 24%, respectively) compared to flowers (18%), fruits (12%), shoots (8%), grasses, tubers, young grooves (each 4%, respectively) and moss (2%). Nutritionally, Anoa consumed 8.8% protein and 25.6% crude fiber. Keywords: Diet Composition, Dung Analysis, Ano

    Diabetic foot ulcer: amputation on request?

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