3,991 research outputs found

    Eikonal profile functions and amplitudes for pp\rm pp and pˉp\bar{\rm p}{\rm p} scattering

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    The eikonal profile function J(b)J(b) obtained from the Model of the Stochastic Vacuum is parametrized in a form suitable for comparison with experiment. The amplitude and the extended profile function (including imaginary and real parts) are determined directly from the complete pp and pˉ\bar{\rm p}p elastic scattering data at high energies. Full and accurate representation of the data is presented, with smooth energy dependence of all parameters. The changes needed in the original profile function required for description of scattering beyond the forward direction are described.Comment: Latex, 28 pages and 16 figure

    High Energy Hadron-Nucleus Cross Sections and Their Extrapolation to Cosmic Ray Energies

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    Old models of the scattering of composite systems based on the Glauber model of multiple diffraction are applied to hadron-nucleus scattering. We obtain an excellent fit with only two free parameters to the highest energy hadron-nucleus data available. Because of the quality of the fit and the simplicity of the model it is argued that it should continue to be reliable up to the highest cosmic ray energies. Logarithmic extrapolations of proton-proton and proton-antiproton data are used to calculate the proton-air cross sections at very high energy. Finally, it is observed that if the exponential behavior of the proton-antiproton diffraction peak continues into the few TeV energy range it will violate partial wave unitarity. We propose a simple modification that will guarantee unitarity throughout the cosmic ray energy region.Comment: 8 pages, 9 postscript figures. This manuscript replaces a partial manuscript incorrectly submitte

    History of Lancaster, New Hampshire.

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    GazeDrone: Mobile Eye-Based Interaction in Public Space Without Augmenting the User

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    Gaze interaction holds a lot of promise for seamless human-computer interaction. At the same time, current wearable mobile eye trackers require user augmentation that negatively impacts natural user behavior while remote trackers require users to position themselves within a confined tracking range. We present GazeDrone, the first system that combines a camera-equipped aerial drone with a computational method to detect sidelong glances for spontaneous (calibration-free) gaze-based interaction with surrounding pervasive systems (e.g., public displays). GazeDrone does not require augmenting each user with on-body sensors and allows interaction from arbitrary positions, even while moving. We demonstrate that drone-supported gaze interaction is feasible and accurate for certain movement types. It is well-perceived by users, in particular while interacting from a fixed position as well as while moving orthogonally or diagonally to a display. We present design implications and discuss opportunities and challenges for drone-supported gaze interaction in public

    Form of analyzing power and the determination of the basic parameters of hadron scattering amplitude

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    The determination of magnitudes of basic parameters of the high energy elastic scattering amplitude are examined at small momentum transfers with taking account of the Coulomb-hadron interference effects.Comment: 6 pages, LaTeX, 4 figures (files.ps), Talk at the International Workshop "Spin and Symmetry" (Prague, Chech., 13-19 July 2000

    Asymptotic behaviour of the total cross section of p-p scattering and the Akeno cosmic ray data

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    I present a new determination of the total cross section for proton-proton collisions from the recent Akeno results on absorption of the cosmic ray protons in the p-Air collisions. Extrapolation to the SSC energy suggests σtot(p−p)≈(160−170)mb\sigma_{tot}(p-p) \approx (160-170) mb. I also comment on a possible sensitivity of the p-Air cross section determinations to assumptions on the inelasticity of nuclear collisions at high energy.Comment: . 6 pages, 0 figure

    Calculations of 8^{8}He+p Elastic Cross Sections Using Microscopic Optical Potential

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    An approach to calculate microscopic optical potential (OP) with the real part obtained by a folding procedure and with the imaginary part inherent in the high-energy approximation (HEA) is applied to study the 8^8He+p elastic scattering data at energies of tens of MeV/nucleon (MeV/N). The neutron and proton density distributions obtained in different models for 8^{8}He are utilized in the calculations of the differential cross sections. The role of the spin-orbit potential is studied. Comparison of the calculations with the available experimental data on the elastic scattering differential cross sections at beam energies of 15.7, 26.25, 32, 66 and 73 MeV/N is performed. The problem of the ambiguities of the depths of each component of the optical potential is considered by means of the imposed physical criterion related to the known behavior of the volume integrals as functions of the incident energy. It is shown also that the role of the surface absorption is rather important, in particular for the lowest incident energies (e.g., 15.7 and 26.25 MeV/nucleon).Comment: 11 pages, 7 figures, accepted for publication in Physical Review

    Diffractive Dissociation and Eikonalization in High Energy pp and p pˉ {\bar p} Collisions

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    We show that eikonal corrections imposed on diffraction dissociation processes calculated in the triple Regge limit, produce a radical change in the energy dependence of the predicted cross section. The induced correction is shown to be in general agreement with the new experimental data measured at the Tevatron.Comment: 11 pages LATEX, ( two figures not included obtainable from authors) (TAUP 2066-93 and FERMILAB PUB 93/ T

    Analisis Asosiasi Daun Sang (Johannesteijsmannia Altifrons) Dengan Jenis-jenis Palem Di Resort Sei Betung, Taman Nasional Gunung Leuser, Kabupaten Langkat, Sumatera Utara

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    Daun Sang is an endemic species that can be found in Gunung Leuser National Park and Bukit Tiga Puluh National Park. This palm is thought to have associations with other palm. Where around Daun Sang grow there are palm types Lipai (Licuala spinosa), but not always around Lipai grow Daun Sang are. Daun Sang need shade to grow because these palm is sensitive to the sunlight. This study aimed to analyze the association of daun sang by some kind of palm that grows around in order to conservation and optimize the cultivation of the daun sang. The method used is a descriptive method with observation of the Daun Sang number and some kind of of palms around it done intentionally (purposive sampling). The method is performed by making 2 plot observations, each size is 100m × 100m, then divided by making the sample plots of 20m × 20m. Observed data were processed using 2 x 2 contingency table, and then calculated by the chi-square test formulations and Jaccard index to calculate the extent of the association. three species of palm found in the study site there are pinanga speciosa, tetradactylus and Plectomiopsis Calamus sp. The results showed that daun sang are not associated with Pinanga speciosa. Association occurs between daun sang with the Calamus tetradactylus and daun sang with Plectomiopsis sp. The highest level of association occurs in Daun Sang and Calamus tetradactylus with maximum association index value of 1. The level of association between Daun Sang with Plectomiopsis sp. approaching the maximum value of the association index in 0.84

    A Transient New Coherent Condition of Matter: The Signal for New Physics in Hadronic Diffractive Scattering

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    We demonstrate the existence of an anomalous structure in the data on the diffractive elastic scattering of hadrons at high energies and small momentum transfer. We analyze five sets of experimental data on p(p‾)−pp(\overline{p})-p scattering from five different experiments with colliding beams, ranging from the first-- and second--generation experiments at s=53\sqrt{s} = 53 GeV to the most recent experiments at 546 GeV and at 1800 GeV. All of the data sets exhibit a localized anomalous structure in momentum transfer. We represent the anomalous behavior by a phenomenological formula. This is based upon the idea that a transient coherent condition of matter occurs in some of the intermediate inelastic states which give rise, via unitarity, to diffractive elastic scattering. The Fourier--Bessel transform into momentum--transfer space of a spatial oscillatory behavior of matter in the impact--parameter plane results in a small piece of the diffractive amplitude which exhibits a localized anomalous behavior near a definite value of −t-t . In addition, we emphasize possible signals coming directly from such a new condition of matter that may be present in current experiments on inelastic processes.Comment: 25 pages, LaTeX (12 figures, not included). A complete postscript file (except figures 1 and 11, which are available upon request) is available via anonymous ftp at ttpux2.physik.uni-karlsruhe.de (129.13.102.139) as /ttp94-03 /ttp94-03.ps, Local preprint# TTP94-03 (March 1994
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