718 research outputs found

    The explicit procedures for reconstruction of full set of helicity amplitudes in elastic proton-proton and proton-antiproton collisions

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    The explicit procedures are described for reconstruction of the full set of helicity amplitudes in proton-proton and proton-antiproton elastic scattering. The procedures are based on the derivative relations for the helicity amplitudes in s-channel, on the explicit parametrization of the leading spin non flip amplitudes and crossing - symmetry relations. Asymptotic theorems are used for definition of free parameters in derivative relations. We also study the Odderon influence on the helicity amplitude reconstruction. Reconstruction procedures are valid at extremely wide energy domain and broad range of momentum transfer. These procedures might be useful in studying the spin phenomena in proton-proton and proton-antiproton elastic scattering.Comment: 4 pages, XVII International Spin Physics Symposium, SPIN2006, October 2-7, 2006, Kyoto, Japa

    A fixed angle double mirror filter for preparing a pink undulator beam at the Advanced Photon Source

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    Recent advances in X-ray Photon Correlation Spectroscopy (XPCS) use the full bandwidth of an undulator harmonic in order to maximize the coherent flux for small angle X-ray scattering experiments. X-ray mirrors and filters are typically used to select a given harmonic of the spectrum. At the University of Michigan/Howard University/Lucent Technologies, Bell Labs, Collaborative Access Team (MHATT-CAT) undulator beamline of the Advanced Photon Source, we have designed a fixed-angle Double Mirror Filter which will provide a “pink beam” (i.e., 2–3% bandwidth) for XPCS experiments. This device uses two small mirrors which vertically reflect a 0.1 mm×0.1 mm0.1mm×0.1mm white beam in a symmetric geometry. The doubly reflected beam propagates parallel to the incident white beam, but is offset vertically by 35 mm. Using the standard offset of the APS allows one to stop the white beam with a standard APS beam stop. In this report, we will describe our design considerations for this instrument. We also report the results of preliminary tests of the performance. The mirrors preserve the transverse coherence of the source, and filter the undulator spectrum as expected. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87429/2/238_1.pd

    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

    Coulomb-hadron phase factor and spin phenomena in a wide region of transfer momenta

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    The Coulomb-hadron interference effects are examined at small and large tt. The methods for the definition of spin-dependent parts of hadron scattering amplitude are presented. The additional contributions to analyzing power ANA_N and the double spin correlation parameter ANNA_{NN} owing to the electromagnetic-hadron interference are determined in the diffraction dip domain of high-energy elastic hadron scattering.Comment: 9 pages, LaTeX, 4 figure
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