8,254,979 research outputs found

    Hard scattering and jets--from p-p collisions in the 1970's to Au+Au collisions at RHIC

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    Hard scattering in p-p collisions, discovered at the CERN ISR in 1972 by the method of leading particles, proved that the partons of Deeply Inelastic Scattering strongly interacted with each other. Further ISR measurements utilizing inclusive single or pairs of hadrons established that high pT particles are produced from states with two roughly back-to-back jets which are the result of scattering of constituents of the nucleons as described by Quantum Chromodynamics (QCD), which was developed during the course of these measurements. These techniques, which are the only practical method to study hard-scattering and jet phenomena in Au+Au central collisions, are reviewed, with application to measurements at RHIC.Comment: 4 pages, 5 figures, Proceedings of Hard Probes 2004, International Conference on Hard and Electromagnetic Probes of High Energy Nuclear Collisions, Nov 4-10, 2004, to appear in EPJ

    Ground State Properties of an Asymmetric Hubbard Model for Unbalanced Ultracold Fermionic Quantum Gases

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    In order to describe unbalanced ultracold fermionic quantum gases on optical lattices in a harmonic trap, we investigate an attractive (U<0U<0) asymmetric (t↑≠t↓t_\uparrow\neq t_\downarrow) Hubbard model with a Zeeman-like magnetic field. In view of the model's spatial inhomogeneity, we focus in this paper on the solution at Hartree-Fock level. The Hartree-Fock Hamiltonian is diagonalized with particular emphasis on superfluid phases. For the special case of spin-independent hopping we analytically determine the number of solutions of the resulting self-consistency equations and the nature of the possible ground states at weak coupling. Numerical results for unbalanced Fermi-mixtures are presented within the local density approximation. In particular, we find a fascinating shell structure, involving normal and superfluid phases. For the general case of spin-dependent hopping we calculate the density of states and the possible superfluid phases in the ground state. In particular, we find a new magnetized superfluid phase.Comment: 9 pages, 5 figure

    Structures of the f0(980)f_0(980), a0(980)a_0(980) mesons and the strong coupling constants gf0K+K−g_{f_0 K^+ K^-}, ga0K+K−g_{a_0 K^+ K^-} with the light-cone QCD sum rules

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    In this article, with the assumption of explicit isospin violation arising from the f0(980)−a0(980)f_0(980)-a_0(980) mixing, we take the point of view that the scalar mesons f0(980)f_0(980) and a0(980)a_0(980) have both strange and non-strange quark-antiquark components and evaluate the strong coupling constants gf0K+K−g_{f_0 K^+ K^-} and ga0K+K−g_{a_0 K^+ K^-} within the framework of the light-cone QCD sum rules approach. The large strong scalar-KKKK couplings through both the nnˉn\bar{n} and ssˉs\bar{s} components gf0K+K−nˉng^{\bar{n}n}_{f_0 K^+ K^-}, gf0K+K−sˉsg^{\bar{s}s}_{f_0 K^+ K^-}, ga0K+K−nˉng^{\bar{n}n}_{a_0 K^+ K^-} and ga0K+K−sˉsg^{\bar{s}s}_{a_0 K^+ K^-}will support the hadronic dressing mechanism, furthermore, in spite of the constituent structure differences between the f0(980)f_0(980) and a0(980)a_0(980) mesons, the strange components have larger strong coupling constants with the K+K−K^+K^- state than the corresponding non-strange ones, gf0K+K−sˉs≈2gf0K+K−nˉng_{f_0 K^+ K^-}^{\bar{s}s}\approx \sqrt{2}g_{f_0 K^+ K^-}^{\bar{n}n} and ga0K+K−sˉs≈2ga0K+K−nˉng_{a_0 K^+ K^-}^{\bar{s}s}\approx \sqrt{2} g_{a_0 K^+ K^-}^{\bar{n}n}. From the existing controversial values, we can not reach a general consensus on the strong coupling constants gf0K+K−g_{f_0 K^+ K^-}, ga0K+K−g_{a_0 K^+ K^-} and the mixing angles.Comment: 14 pages; Revised versio

    Circular 97

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    A yield trial in which 43 named varieties and one numbered selection of potatoes were compared was conducted during the 1993 growing season at the University of Alaska Fairbanks, Agricultural and Forestry Experiment Station’s Palmer Research Center, Matanuska Farm, located six miles west of Palmer, Alaska.Potato Variety Performance -- Introduction -- Matanuska Farm Yield Trials: Cultural Practices and Environmental Conditions; Results and Discussion -- Trials at Other Locations in Alaska: General Procedures; Site-Specific Information; Delta Junction; Fairbanks; Homer; Kenai-Soldotna; Nom

    Summary, DIS 97

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    Some of the experimental and theoretical results discussed at the Fifth International Workshop on Deep Inelastic Scattering and QCD are reviewed.Comment: 33 pages, LaTeX, 14 eps figures. Summary talk, to appear in Proceedings of the Fifth International Workshop on Deep Inelastic Scattering and QC

    Application of the Two-Scale Model to the HERMES Data on Nuclear Attenuation

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    The Two-Scale Model and its improved version were used to perform the fit to the HERMES data for Μ\nu (the virtual photon energy) and z (the fraction of Μ\nu carried by hadron) dependencies of nuclear multiplicity ratios for π+\pi^+ and π−\pi^- mesons electro-produced on two nuclear targets (14^{14}N and 84^{84}Kr). The quantitative criterium χ2\chi ^2 was used for the first time to analyse the results of the model fit to the nuclear multiplicity ratios data. The two-parameter's fit gives satisfactory agreement with the HERMES data. Best values of the parameters were then used to calculate the Μ\nu- and zz - dependencies of nuclear attenuation for π0\pi^0, K+^+, K−^- and pˉ\bar{p} produced on 84^{84}Kr target, and also make a predictions for Μ\nu, z and the Q2^2 (the photon virtuality) - dependencies of nuclear attenuation data for those identified hadrons and nuclea, that will be published by HERMES

    Basketball Guide, 1996-97

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    Denying equality: an analysis of arguments against lowering the age of consent for sex between men

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    This paper takes a human rights approach to lesbian and gay oppression and critically explores the arguments used to oppose equality in the debates about the age of consent for sex between men. A thematic analysis of Hansard and newspaper reports produced in Britain during the 1990s showed that opponents of the amendment to equalise the age of consent countered with three key arguments laying claim to ethical principles overriding the principle of equality. These were: (1) Principles of right and wrong take precedence over equality; (2) Principles of democracy take precedence over equality; (3) Principles of care and protection take precedence over equality. Two additional arguments (the health risks of anal intercourse, and escalating demands for gay rights) are also outlined. Our findings are discussed with reference to debates on other lesbian and gay rights issues, and we consider the ways in which we might best counter these arguments. </p

    Analyzing Framing Effecty by an Experiment among Students in Turkey

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    This study investigates the framing effect of experiments that conducted among students. The main aim of this work is to show the results of an experiment conducted in Turkey how could affect behavior of subjects who were students in banking and insurance business studies department. By expressing a particular topic in negative and positive way we could observe the behaviors. In conclusion, these subjects mainly focused on positive expression to avoid risks

    Revisiting Antitrust Limits to Probabilistic Patent Disputes: Strategic Entry and Asymmetric Information

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    We consider separately strategic entry and asymmetric information in the design of the settlement policy governing patent disputes, with a focus on Shapiro (2003)’s consumer protection rule. We show that, when a potential entrant strategically incurs an entry cost before engaging in a patent dispute, a more stringent settlement policy of deterring costly entry is preferable to the patent-holder and may lead to higher static efficiency. Concerning asymmetric information, when the disputants, but not the court, learn the patent validity, we derive an “expectation test,” which requires that a laxer settlement policy be coupled with higher expected patent validity under settlement
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