1,331 research outputs found

    Absence of Nonlocal Counter-terms in the Gauge Boson Propagator in Axial -type Gauges

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    We study the two-point function for the gauge boson in the axial-type gauges. We use the exact treatment of the axial gauges recently proposed that is intrinsically compatible with the Lorentz type gauges in the path-integral formulation and has been arrived at from this connection and which is a ``one-vector'' treatment. We find that in this treatment, we can evaluate the two-point functions without imposing any additional interpretation on the axial gauge 1/(n.q)^p-type poles. The calculations are as easy as the other treatments based on other known prescriptions. Unlike the ``uniform-prescription'' /L-M prescription, we note, here, the absence of any non-local divergences in the 2-point proper vertex. We correlate our calculation with that for the Cauchy Principal Value prescription and find from this comparison that the 2-point proper vertex differs from the CPV calculation only by finite terms. For simplicity of treatment, the divergences have been calculated here with n^2>0 and these have a smooth light cone limit.Comment: 17 pages; 3 figures drawn using feyn.st

    Some Observations on Non-covariant Gauges and the epsilon-term

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    We consider the Lagrangian path-integrals in Minkowski space for gauges with a residual gauge-invariance. From rather elementary considerations, we demonstrate the necessity of inclusion of an epsilon-term (even) in the formal treatments, without which one may reach incorrect conclusions. We show, further, that the epsilon-term can contribute to the BRST WT-identities in a nontrivial way (even as epsilon-->0). We also show that the (expectation value of the) correct epsilon-term satisfies an algebraic condition. We show by considering (a commonly used) example of a simple local quadratic epsilon -term, that they lead to additional constraints on Green's function that are not normally taken into account in the BRST formalism that ignores the epsilon-term, and that they are characteristic of the way the singularities in propagators are handled. We argue that for a subclass of these gauges, the Minkowski path-integral could not be obtained by a Wick rotation from a Euclidean path-integral.Comment: 12 pages, LaTeX2

    Evaluation of Economic Losses due to Coccidiosis in Poultry Industry in India

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    Coccidiosis is an old parasitic disease, prevalent all over the country and has a significant impact on poultry production. In this paper, economic loss to poultry industry has been estimated considering the major economic parameters. The estimation has revealed that commercial broiler industry is a major sufferer due to coccidiosis wherein 95.61 per cent of the total economic loss occurs due to the disease. The commercial layer industry shares 3.53 per cent economic loss, mainly due to cost of chemoprophylaxis and reduced egg production. A comparison across economic traits has revealed that loss is maximum due to reduced body weight gain, followed by increased FCR (23.74%) and chemoprophylaxis (2.83%) in the total loss due to coccidiosis in broiler industry of India. The overall comparison of economic traits for all the types of poultry sector it has shown that reduced body wt gain and increased FCR are the major parameters from which 68.08 per cent and 22.70 per cent annual loss has occurred in the total loss from coccidiosis in India during the year 2003-04. The total loss due to coccidiosis has been found to be of Rs 1.14 billion (approx) for the year 2003-04. The study has observed that generation of this data across different geographical regions will be helpful to conclude about the global economic loss due to coccidiosis in the poultry industry.Agricultural and Food Policy,

    Relating Green's Functions in Axial and Lorentz Gauges using Finite Field-Dependent BRS Transformations

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    We use finite field-dependent BRS transformations (FFBRS) to connect the Green functions in a set of two otherwise unrelated gauge choices. We choose the Lorentz and the axial gauges as examples. We show how the Green functions in axial gauge can be written as a series in terms of those in Lorentz gauges. Our method also applies to operator Green's functions. We show that this process involves another set of related FFBRS transfomations that is derivable from infinitesimal FBRS. We suggest possible applications.Comment: 20 pages, LaTex, Section 4 expanded, typos corrected; last 2 references modified; (this) revised version to appear in J. Math. Phy

    Possible Detection of Causality Violation in a Non-local Scalar Model

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    We consider the possibility that there may be causality violation detectable at higher energies. We take a scalar nonlocal theory containing a mass scale Λ\Lambda as a model example and make a preliminary study of how the causality violation can be observed. We show how to formulate an observable whose detection would signal causality violation. We study the range of energies (relative to Λ\Lambda) and couplings to which the observable can be used.Comment: Latex, 30 page

    Wilson Loop and the Treatment of Axial Gauge Poles

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    We consider the question of gauge invariance of the Wilson loop in the light of a new treatment of axial gauge propagator proposed recently based on a finite field-dependent BRS (FFBRS) transformation. We remark that as under the FFBRS transformation the vacuum expectation value of a gauge invariant observable remains unchanged, our prescription automatically satisfies the Wilson loop criterion. Further, we give an argument for {\it direct} verification of the invariance of Wilson loop to O(g^4) using the earlier work by Cheng and Tsai. We also note that our prescription preserves the thermal Wilson loop to O(g^2).Comment: 8 pages, LaTex; some typos related to equation (18) correcte

    Lime Slurry Injection, Lime Piles and Stone Columns for Improvement of Soft Soils − Field Trials

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    Scarcity of good land available for construction has resulted in development of a number of techniques for improvement of ground. If properly treated, most soils can be made into useful construction materials. Two case histories arc presented utilizing two different kinds of ground improvement techniques. Field scale trials are conducted to reinforce deep deposit of soft marine clay with stone columns and a road embankment made with black cotton soil modified with lime columns and pressure injection of lime slurry. Both techniques resulted in significant improvement in strength and settlement characteristics

    Deep Retrofit System Solution Assessment for Philadelphia Navy Yard Office Buildings

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    Initial assessments of economically attractive integrated building energy system solutions that can substantially reduce energy consumption in two medium-sized office buildings in the Philadelphia Navy Yard are presented. These sites were selected because they are the current and future headquarters of the DOE Energy Efficient Buildings Hub (EEB HUB). Energy efficient retrofit solutions involving integrated building systems with 40-60% site- and source-energy reduction potential relative to selected baseline energy consumption configurations are identified. The scope of retrofit options explored and integrated involve the building envelope, lighting and HVAC systems as well as the related control systems, providing a spectrum of retrofit options that range from low-/no-cost options to relatively higher capital cost options that involve significant capital upgrades and facility renovations. The energy savings estimates are based on combining multiple energy conservation measures (ECMs) that are tailored to the building use type and climate conditions. Energy performance (energy savings potential) and economic impact (NPV, IRR, and simple payback) of these retrofit system solution recommendations are assessed for two office buildings – Building 101 and Building 661, at the Philadelphia Navy Yard. A suite of retrofit system packages is presented for each building with a range of initial investments and economic returns to assist the investment decision making process, by stakeholders such as the building owner and operator. Results of the cost benefit analyses will be presented in light of incentives for high performance office buildings in the Philadelphia ten-county region
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