27,405 research outputs found

    Can CPT Symmetry Be Tested With K^0 vs \bar{K}^0--> \pi^+\pi^-\pi^0 Decays?

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    We show that the CP-violating effect in K^0 vs \bar K^0-->\pi^+\pi^-\pi^0 decays differs from that in K_{\rm L}-->\pi^+\pi^-, K_{\rm L}-->\pi^0\pi^0 or the semileptonic K_{\rm L} transitions, if there exists CPT violation in K^0-\bar{K}^0 mixing. A delicate measurement of this difference in the KTeV experiment and at the \phi factory will provide a new test of CPT symmetry in the neutral kaon system.Comment: RevTex 6 pages. Phys. Rev. D (in printing

    Energy Loss and Flavor Dynamics from Single Particle Measurements in PHENIX

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    The transverse momentum spectra, yields, and ratios of charged pions, protons, and antiprotons have been studied up to 5 GeV/c in pTp_T in 5 different centrality classes in Au+Au collisions at sNN\sqrt{s_{NN}} = 200 GeV. These results are compared and contrasted with the observables calculated in recombination models of hadronization. They are also used to examine the color charge dependence of parton energy loss in the medium.Comment: 4 pages, 6 figures, to appear in the Proceedings of Quark Matter 200

    Euler Integration of Gaussian Random Fields and Persistent Homology

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    In this paper we extend the notion of the Euler characteristic to persistent homology and give the relationship between the Euler integral of a function and the Euler characteristic of the function's persistent homology. We then proceed to compute the expected Euler integral of a Gaussian random field using the Gaussian kinematic formula and obtain a simple closed form expression. This results in the first explicitly computable mean of a quantitative descriptor for the persistent homology of a Gaussian random field.Comment: 21 pages, 1 figur

    Aluminum alloys with improved strength

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    Mechanical strength and stress corrosion of new BAR and 7050 alloys that include Zn instead of Cr have been studied and compared with those of 7075 aluminum alloy. Added mechanical strength of new alloys is attributed to finer grain size of 5 to 8 micrometers, however, susceptibility to stress corrosion attack is increased

    Algebraic and geometric aspects of generalized quantum dynamics

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    \noindent We briefly discuss some algebraic and geometric aspects of the generalized Poisson bracket and non--commutative phase space for generalized quantum dynamics, which are analogous to properties of the classical Poisson bracket and ordinary symplectic structure.Comment: 10pages,revtex, IASSNSHEP-93/5

    Avoidance of stress corrosion susceptibility in high strength aluminum alloys by control of grain boundary and matrix microstructure

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    The relation of microstructure to the mechanical strength and stress corrosion resistance of highest strength and overaged tempers of BAR and 7050 aluminum alloys was investigated. Comparison is made with previously studied 7075 aluminum alloy. Optical microscopy, transmission electron microscopy, and differential scanning calorimetry were used to characterize the grain morphology, matrix microstructure, and grain boundary microstructure of these tempers. Grain boundary interparticle spacing was significant to stress corrosion crack propagation for all three alloys; increasing interparticle spacing led to increased resistance to crack propagation. In addition, the fire grain size in Bar and 7050 appears to enhance crack propagation. The highest strength temper of 7050 has a comparatively high resistance to crack initiation. Overall stress corrosion behavior is dependent on environment pH, and evaluation over a range of pH is recommended

    The Legal, Ethical, and Social Implications of the Reasonable Woman Standard in Sexual Harassment Cases

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    In this Article, Professors Adler and Peirce examine the development and implications of the reasonable woman standard that is gaining increasing acceptance as the appropriate gauge for measuring the offensiveness of the conduct at issue in sexual harassment cases. The authors begin by reviewing the origins of sexual harassment law under Title VII of the Civil Rights Act of 1964, paying particular attention to the history of hostile environment causes of action. Professors Adler and Peirce then discuss how and why the reasonable woman standard evolved as an alternative to the conventional reasonable man and reasonable person standards that had been the usual measures of culpable conduct in sexual harassment cases, and how courts have applied the reasonable woman standard in cases involving a wide range of allegedly harassing behaviors. The authors conclude by discussing a variety of important concerns raised by the implementation of the reasonable woman standard, including the fundamental question of whether it is fair to hold men to a standard of conduct that, because they are men, they may be unable to understand or appreciate fully

    Parton recombination at all pTp_T

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    Hadron production at all pTp_T in heavy-ion collisions in the framework of parton recombination is reviewed. It is shown that the recombination of thermal and shower partons dominates the hadron spectra in the intermediate pTp_T region. In d+Aud+Au collisions, the physics of particle production at any η\eta is basically the same as at η=0\eta=0. The Cronin effect is described as a result of the final-state instead of the initial-state interaction. The suppression of RCPR_{CP} at high η\eta is due to the reduction of the soft parton density on the deuteron side, thus resulting in less pions produced by recombination, an explanation that requires no new physics. In Au+AuAu+Au collisions large p/πp/\pi ratio is obtained because the thermal partons can contribute to the formation of proton more than they do to the pion.Comment: 12 pages + 5 figures. Invited talk at Hard Probes 200

    Rossby waves and α\alpha-effect

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    Rossby waves drifting in the azimuthal direction are a common feature at the onset of thermal convective instability in a rapidly rotating spherical shell. They can also result from the destabilization of a Stewartson shear layer produced by differential rotation as expected in the liquid sodium experiment (DTS) working in Grenoble, France. A usual way to explain why Rossby waves can participate to the dynamo process goes back to Busse (1975). In his picture, the flow geometry is a cylindrical array of parallel rolls aligned with the rotation axis. The axial flow component (the component parallel to the rotation axis) is (i) maximum in the middle of each roll and changes its sign from one roll to the next. It is produced by the Ekman pumping at the fluid containing shell boundary. The corresponding dynamo mechanism can be explained in terms of an α\alpha-tensor with non-zero coefficients on the diagonal. In rapidly rotating objects like the Earth's core (or in a fast rotating experiment), Rossby waves occur in the limit of small Ekman number (≈10−15\approx 10^{-15}). In that case, the main source of the axial flow component is not the Ekman pumping but rather the ``geometrical slope effect'' due to the spherical shape of the fluid containing shell. This implies that the axial flow component is (ii) maximum at the borders of the rolls and not at the centers. If assumed to be stationary, such rolls would lead to zero coefficients on the diagonal of the α\alpha-tensor, making the dynamo probably less efficient if possible at all. Actually, the rolls are drifting as a wave, and we show that this drift implies non--zero coefficients on the diagonal of the α\alpha-tensor. These new coefficients are in essence very different from the ones obtained in case (i) and cannot be interpreted in terms of the heuristic picture of Busse (1975)
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