17,303 research outputs found

    Space-Time Exchange Invariance: Special Relativity as a Symmetry Principle

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    Special relativity is reformulated as a symmetry property of space-time: Space-Time Exchange Invariance. The additional hypothesis of spatial homogeneity is then sufficient to derive the Lorentz transformation without reference to the traditional form of the Principle of Special Relativity. The kinematical version of the latter is shown to be a consequence of the Lorentz transformation. As a dynamical application, the laws of electrodynamics and magnetodynamics are derived from those of electrostatics and magnetostatics respectively. The 4-vector nature of the electromagnetic potential plays a crucial role in the last two derivations

    Calculation of The Lifetimes of Thin Stripper Targets Under Bombardment of Intense Pulsed Ions

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    The problems of stripper target behavior in the nonstationary intense particle beams are considered. The historical sketch of studying of radiation damage failure of carbon targets under ion bombardment is presented. The simple model of evaporation of a target by an intensive pulsing beam is supposed. Stripper foils lifetimes in the nonstationary intense particle can be described by two failure mechanisms: radiation damage accumulation and evaporation of target. At the maximal temperatures less than 2500K the radiation damage are dominated; at temperatures above 2500K the mechanism of evaporation of a foil prevails. The proposed approach has been applied to the discription of behaviour of stripper foils in the BNL linac and SNS conditions.Comment: 12 pages, 5 figure

    On the symmetry breaking phenomenon

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    We investigate the problem of symmetry breaking in the framework of dynamical systems with symmetry on a smooth manifold. Two cases will be analyzed: general and Hamiltonian dynamical systems. We give sufficient conditions for symmetry breaking in both cases

    Polarization of Astronomical Maser Radiation. IV. Circular Polarization Profiles

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    Profile comparison of the Stokes parameters VV and II is a powerful tool for maser data analysis, providing the first direct methods for unambiguous determination of (1) the maser saturation stage, (2) the amplification optical depth and intrinsic Doppler width of unsaturated masers, and (3) the comparative magnitudes of Zeeman splitting and Doppler linewidth. Circular polarization recently detected in OH 1720 MHz emission from the Galactic center appears to provide the first direct evidence for maser saturation.Comment: 14 pages, 1 Postscript figures (included), uses aaspp4.sty. To appear in Astrophysical Journa

    Searching for a heavy Higgs boson via the H --> l nu jj decay mode at the CERN LHC

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    The discovery of a heavy Higgs boson with mass up to m_H = 1 TeV at the CERN LHC is possible in the H--> W^+W^- --> l nu jj decay mode. The weak boson scattering signal and backgrounds from t\bar tjj and from W+jets production are analyzed with parton level Monte Carlo programs which are built on full tree level amplitudes for all subprocesses. The use of double jet tagging and the reconstruction of the W invariant mass reduce the combined backgrounds to the same level as the Higgs signal. A central mini-jet veto, which distinguishes the different gluon radiation patterns of the hard processes, further improves the signal to background ratio to about 2.5:1, with a signal cross section of 1 fb. The jet energy asymmetry of the W --> jj decay will give a clear signature of the longitudinal polarization of the W's in the final event sample.Comment: 23 pages (with 7 embedded figures), Revtex, uses epsf.sty. Z-compressed postscript version also available at http://phenom.physics.wisc.edu/pub/preprints/1997/madph-97-1017.ps.Z or at ftp://phenom.physics.wisc.edu/pub/preprints/1997/madph-97-1017.ps.

    Hadronic Production of the Doubly Charmed Baryon Ξcc\Xi_{cc} with Intrinsic Charm

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    The effects of the intrinsic charm on the hadronic production of Ξcc\Xi_{cc} are studied. By taking reasonable intrinsic charm component into account, the change of the theoretical prediction on the production of Ξcc\Xi_{cc} for LHC and Tevatron is small, but in contrast it may enhance significantly for SELEX. The reason is that the collision energy at LHC and Tevatron is so large that the gluon-gluon fusion sub-process, which is irrelevant to intrinsic charm, becomes dominant. But the situation for SELEX is quite different. Our numerical results for SELEX show that by considering all the contributions from various sub-processes, the predicted cross-section may be enhanced by a factor so big as 10210^2 due to a modulating intrinsic charm being taken into account. Therefore, the hadronic production of Ξcc\Xi_{cc} at SELEX may be sensitive enough in observing the intrinsic charm inside the incident hadrons.Comment: 18 pages, 8 figures. More discussions are adde

    Generalized coordinates on the phase space of Yang-Mills theory

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    We study the suitability of complex Wilson loop variables as (generalized) coordinates on the physical phase space of SU(2)SU(2)-Yang-Mills theory. To this end, we construct a natural one-to-one map from the physical phase space of the Yang-Mills theory with compact gauge group GG to a subspace of the physical configuration space of the complex G^\C-Yang-Mills theory. Together with a recent result by Ashtekar and Lewandowski this implies that the complex Wilson loop variables form a complete set of generalized coordinates on the physical phase space of SU(2)SU(2)-Yang-Mills theory. They also form a generalized canonical loop algebra. Implications for both general relativity and gauge theory are discussed.Comment: TeX, 11pp, revised version (minor clarifications added, Comment after (2.9) inserted); to appear in Class. Quant. Grav

    A QCD Calculation of the Interaction of Quarkonium with Nuclei

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    The interaction of quarkonium with nuclei is studied in the mQ→∞m_Q\rightarrow \infty limit of QCD, where the binding energy is found to be exactly computable. The dominant contribution to the interaction is from two-gluon operators. The forward matrix elements of these two-gluon operators can be determined from the QCD scale anomaly, and from deep inelastic scattering. We apply our results to the Υ\Upsilon and J/ψJ/\psi, treating the \qqbar interaction as purely Coulombic. We find the Υ\Upsilon binds in nuclear matter with a binding energy of a few \mev, while for the J/ψJ/\psi binding is of order 10 \mev. For the J/ψJ/\psi in particular we expect confinement effects to produce large corrections to this result.Comment: (10 pages
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