1,489 research outputs found

    Electroweak Baryogenesis in the Next to Minimal Supersymmetric Model

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    In the electroweak phase transition there arises the problem of baryon number washout by sphaleron transitions, which can be avoided if the phase transition is strongly enough first order. The minimal supersymmetric standard model has just two Higgs doublets H1 and H2, while the next to minimal model, NMSSM, has an additional singlet, N, this latter giving rise to the helpful feature that the Higgs potential contains a tree level trilinear field term. We use the tunneling criterion for the existence of a first order electroweak phase change. A quantitative statistical analysis indicates that with parameters of the NMSSM satisfying the experimental constraints a strong first order phase change occurs in about 50% of cases.Comment: 15 pages, plain LaTe

    Scalar-Tensor Theory of Gravity and Generalized Second Law of Thermodynamics on the Event Horizon

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    In blackhole physics, the second law of thermodynamics is generally valid whether the blackhole is a static or a non-static one. Considering the universe as a thermodynamical system the second law of blackhole dynamics extends to the non-negativity of the sum of the entropy of the matter and the horizon, known as generalized second law of thermodynamics(GSLT). Here, we have assumed the universe to be bounded by the event-horizon or filled with perfect fluid and holographic dark energy in two cases. Thus considering entropy to be an arbitrary function of the area of the event-horizon, we have tried to find the conditions and the restrictions over the scalar field and equation of state for the validity of the GSLT and both in quintessence-era and in phantom-era in scalar tensor theory.Comment: 8 page

    Generalized Second Law of Thermodynamics on the Event Horizon for Interacting Dark Energy

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    Here we are trying to find the conditions for the validity of the generalized second law of thermodynamics (GSLT) assuming the first law of thermodynamics on the event horizon in both cases when the FRW universe is filled with interacting two fluid system- one in the form of cold dark matter and the other is either holographic dark energy or new age graphic dark energy. Using the recent observational data we have found that GSLT holds both in quintessence era as well as in phantom era for new age graphic model while for holographic dark energy GSLT is valid only in phantom era.Comment: 8 pages, 2 figure

    Deconstruction, Lattice Supersymmetry, Anomalies and Branes

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    We study the realization of anomalous Ward identities in deconstructed (latticized) supersymmetric theories. In a deconstructed four-dimensional theory with N=2 supersymmetry, we show that the chiral symmetries only appear in the infrared and that the anomaly is reproduced in the usual framework of lattice perturbation theory with Wilson fermions. We then realize the theory on the world-volume of fractional D-branes on an orbifold. In this brane realization, we show how deconstructed theory anomalies can be computed via classical supergravity. Our methods and observations are more generally applicable to deconstructed/latticized supersymmetric theories in various dimensions.Comment: 1+27 pages, 2 figures, references adde

    First-principles Calculation of the Formation Energy in MgO-CaO Solid Solutions

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    The electronic structure and total energy were calculated for ordered and disordered MgO-CaO solid solutions within the multiple scattering theory in real space and the local density approximation. Based on the dependence of the total energy on the unit cell volume the equilibrium lattice parameter and formation energy were determined for different solution compositions. The formation energy of the solid solutions is found to be positive that is in agreement with the experimental phase diagram, which shows a miscibility gap.Comment: 11 pages, 3 figure

    The Impact of Interorganizational Imitation on New Venture International Entry and Performance

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    We examine the impact of interorganizational imitation on new venture international entry and subsequent performance. Using a sample of 150 U.S.-based publicly held new ventures, we find that new venture international entry is in part an imitative response to the internationalization of other firms in the venture\u27s home country industry and/or subsets of firms with certain traits or outcomes. We also find that interorganizational imitation moderates the relationship between new venture international entry and profitability, but not the relationship between new venture international entry and sales growth. These findings contribute to the growing body of literature on new venture internationalization

    Does entropic force always imply the Newtonian force law?

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    We study the entropic force by introducing a bound S≤A3/4S \le A^{3/4} between entropy and area which was derived by imposing the non-gravitational collapse condition. In this case, applying a modified entropic force to this system does not lead to the Newtonian force law.Comment: 11 pages, version to appear in EPJ

    ON THE INTRINSIC CHARM COMPONENT OF THE NUCLEON

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    Using a D‾\overline D meson cloud model we calculate the squared charm radius of the nucleon . The ratio between this squared radius and the ordinary baryon squared radius is identified with the probability of ``seeing'' the intrinsic charm component of the nucleon. Our estimate is compatible with those used to successfully describe the charm production phenomenology.Comment: 9 pages, 2 figures not included, avaiable from the author

    Validity of the Generalized Second Law of Thermodynamics of the Universe Bounded by the Event Horizon in Holographic Dark Energy Model

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    In this letter, we investigate the validity of the generalized second law of thermodynamics of the universe bounded by the event horizon in the holographic dark energy model. The universe is chosen to be homogeneous and isotropic and the validity of the first law has been assumed here. The matter in the universe is taken in the form of non-interacting two fluid system- one component is the holographic dark energy model and the other component is in the form of dust.Comment: 8 page

    Kaluza-Klein Cosmology With Modified Holographic Dark Energy

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    We investigate the compact Kaluza-Klein cosmology in which modified holographic dark energy is interacting with dark matter. Using this scenario, we evaluate equation of state parameter as well as equation of evolution of the modified holographic dark energy. Further, it is shown that the generalized second law of thermodynamics holds without any constraint.Comment: 13 pages, accepted for publication in Gen. Relativ. Gravi
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