762 research outputs found

    Drell-Yan Production of Z' in the Three-Site Higgsless Model at the LHC

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    In the Higgsless models, there are extra gauge bosons which keep the perturbative unitarity of a longitudinally polarized gauge boson. The three-site Higgsless model is a minimal Higgsless model and contains three extra gauge bosons, W′±W^{\prime \pm} and Z'. In this paper, we report the discovery potential of the Z' gauge boson via Drell-Yan production with Z'(mass=380, 500, 600 GeV) →WW→ℓνqq\rightarrow WW \rightarrow \ell\nu qq (ℓ=e\ell=e, μ\mu) at the LHC (s\sqrt{s}=14 TeV).Comment: 7 pages, 5 figures included. References revise

    N=1 Supersymmetric SU(2)rSU(2)^r Moose Theories

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    We study the quantum moduli spaces and dynamical superpotentials of four dimensional SU(2)rSU(2)^r linear and ring moose theories with N=1\mathcal{N}=1 supersymmetry and link chiral superfields in the fundamental representation. Nontrivial quantum moduli spaces and dynamical superpotentials are produced. When the moduli space is perturbed by generic tree level superpotentials, the vacuum space becomes discrete. The ring moose is in the Coulomb phase and we find two singular submanifolds with a nontrivial modulus that is a function of all the independent gauge invariants needed to parameterize the quantum moduli space. The massive theory near these singularities confines. The Seiberg-Witten elliptic curve that describes the quantum moduli space of the ring moose is produced.Comment: 26 pages, 4 figures. A few comments and references added. To appear in PR

    Dynamic Linear Programming Model for Agricultural Investment and Resources Utilization Policies

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    In this paper a dynamic linear programming model for large scale farm development is presented. Special emphasis is placed upon the modelling of investment policies and associated resource utilization programs. Firstly, a flexible modelling procedure to handle capital input constraints of farms is outlined. In the second half of the study a dynamic linear programming model covering the whole farming system and the whole planning horizon is described. The paper concludes by summarizing the experiences gained in Hungary in the use of different linear and dynamic linear programming models of agricultural development

    How Well Does AdS/QCD Describe QCD?

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    AdS/QCD is an extra-dimensional approach to modeling hadronic physics, motivated by the AdS/CFT correspondence in string theory. AdS/QCD models are often more accurate than would have been expected at energies below a few GeV. We address the question of why these models are so successful, and respond to some of the criticisms that have been waged against these models.Comment: To appear in proceedings of Crossing the Boundaries: Gauge Dynamics at Strong Coupling (Shifmania), Minnesota, May 14-17, 2009. 12 pages, 2 eps figure

    Inhomogeneous Equation of State of the Universe: Phantom Era, Future Singularity and Crossing the Phantom Barrier

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    The dark energy universe equation of state (EOS) with inhomogeneous,Hubble parameter dependent term is considered. The motivation to introduce such a term comes from time-dependent viscosity considerations and modifications of general relativity. For several explicit examples of such EOS it is demonstrated how the type of future singularity changes, how the phantom epoch emerges and how crossing of phantom barrier occurs. Similar cosmological regimes are considered for the universe with two interacting fluids and for universe with implicit EOS. For instance, the crossing of phantom barrier is realized in easier way, thanks to the presence of inhomogeneous term. The thermodynamical dark energy model is presented where the universe entropy may be positive even at phantom era as a result of crossing of w=-1 barrier.Comment: LaTeX, 13 pages, refs. added, version to appear in PR

    Detecting Axion-Like Particles With Gamma Ray Telescopes

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    We propose that axion-like particles (ALPs) with a two-photon vertex, consistent with all astrophysical and laboratory bounds, may lead to a detectable signature in the spectra of high-energy gamma ray sources. This occurs as a result of gamma rays being converted into ALPs in the magnetic fields of efficient astrophysical accelerators according to the "Hillas criterion", such as jets of active galactic nuclei or hot spots of radio galaxies. The discovery of such an effect is possible by GLAST in the 1-100 GeV range and by ground based gamma ray telescopes in the TeV range.Comment: corrected typos, one plot modified, material rearranged for clarification. Conclusions unchanged. Matches version published in Phys. Rev. Let

    QCD4_4 Glueball Masses from AdS-6 Black Hole Description

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    By using the generalized version of gauge/gravity correspondence, we study the mass spectra of several typical QCD4_4 glueballs in the framework of AdS6_6 black hole metric of Einstein gravity theory. The obtained glueball mass spectra are numerically in agreement with those from the AdS7Ă—S47 \times S^4 black hole metric of the 11-dimensional supergravity.Comment: 10 pages, references updated and minor change

    On Gauge Dynamics and SUSY Breaking in Orientiworld

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    In the Orientiworld framework the Standard Model fields are localized on D3-branes sitting on top of an orientifold 3-plane. The transverse 6-dimensional space is a non-compact orbifold (or a more general conifold). The 4-dimensional gravity on D3-branes is reproduced due to the 4-dimensional Einstein-Hilbert term induced at the quantum level. The orientifold 3-plane plays a crucial role, in particular, without it the D3-brane world-volume theories would be conformal due to the tadpole cancellation. We study non-perturbative gauge dynamics in various N=1 supersymmetric orientiworld models based on the Z_3 as well as Z_5 and Z_7 orbifold groups. Our discussions illustrate that there is a rich variety of supersymmetry preserving dynamics in some of these models. On the other hand, we also find some models with dynamical supersymmetry breaking.Comment: 21 pages, revtex, minor misprints corrected (to appear in Int. J. Mod. Phys. A

    Inflating Intersecting Branes and Remarks on the Hierarchy Problem

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    We generalize solutions of Einstein's equations for intersecting branes in higher dimensional spacetimes to the nonstatic case, modeling an expanding universe. The relation between the Hubble rate, the brane tensions, and the bulk cosmological constant is similar to the case of a single 3-brane in a 5-dimensional spacetime. However, because the bulk inflates as well as the branes, this class of solutions suffers from Newton's constant tending toward zero on the TeV brane, where the Randall-Sundrum mechanism should solve the weak scale hierarchy problem. The strength of gravity remains constant on the Planck brane, however.Comment: 10 pages, LaTeX. v2:Misprint in eq. (23) corrected; citations fixed and clarified relationship of our work to hep-th/9909053 and hep-th/9909076 v3: final version to appear in PLB. Corrected discussion of the time dependance of the 4-D Planck mass on the TeV brane. Some references added to earlier works on warped Kaluza-Klein compactification
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