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  1. The extraction of Φ – N total cross section from d ( γ , p K + K - ) n

    Qian, X. ; Chen, W. ; Gao, H. ; ... - Physics Letters. B
    We report on the first measurement of the differential cross section of $$\phi$$-meson photoproduction for the $$d(\gamma,pK^{+}K^{-})n$$ exclusive reaction channel. The experiment was performed using a \textcolor{black}{tagged-photon} beam and the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. A combined analysis using data from the $$d(\gamma,pK^{+}K^{-})n$$ channel and those from a previous publication on coherent $$\phi$$ production on the deuteron has been carried out to extract the $$\phi-N$$ total cross section, $$\sigma_{\phi N}$$. The extracted $$\phi-N$$ total cross section favors a value above 20 mb. This value is larger than the value extracted using vector-meson dominance models for $$\phi$$ photoproductionmore » on the proton.« less

  2. Using the top quark for testing standard-model polarization and CP predictions

    Kane, G. L. ; Ladinsky, G. A. ; Yuan, C. -P. - Physical Review. D, Particles Fields
    Once top quarks are found, because they are heavy they will allow many new tests of the standard model (SM) and new probes of physics at the 100-GeV scale. In this paper we show how to test the standard-model QCD predictions for the transverse polarization of a top quark produced at the Fermilab Tevatron, Superconducting Super Collider, CERN Large Hadron Collider, and the Next Linear Collider. We also examine the most general form of the W – t – b vertex, and show how to detect effects of non-SM operators. Ways of detecting non-SM CP-violation effects in either the productionmore » or the decay of the top quarks and top antiquarks are examined.« less

  3. Water Cooled Targets for Intense Ion Beams

    Hanley, P. R. ; Haberl, A. W. ; Taylor, A. - IEEE Transactions on Nuclear Science
    Target backings cooled by water in linear flow have proven capable of dissipating heat loads from 2 kW ion beams focused to about 20 mm2 for extended periods without structural failure. In addition to the more obvious modes of failure by plastic deformation and melting, metallographic studies of damaged targets have revealed deep void penetrations along grain boundaries. The targetry limitations imposed on maximum usable beam power by heat transfer from the backing to the cooling fluid have been investigated. Finally, neutron producing lifetimes of LiF targets have been compared for different proton beam and coolant flow conditions.

  4. Fixed-Field Alternating-Gradient Particle Accelerators

    Symon, K. R. ; Kerst, D. W. ; Jones, L. W. ; ... - Physical Review
    It is possible, by using alternating-gradient focusing, to design circular accelerators with magnetic guide fields which are constant in time, and which can accommodate stable orbits at all energies from injection to output energy. Such accelerators are in some respects simpler to construct and operate, and moreover, they show promise of greater output currents than conventional synchrotrons and synchrocyclotrons. Two important types of magnetic field patterns are described, the radial-sector and spiral-sector patterns, the former being easier to understand and simpler to construct, the latter resulting in a much smaller accelerator for a given energy. Further, a theory of orbitsmore » in fixed-field alternating-gradient accelerators has been worked out in linear approximation, which yields approximate general relationships between machine parameters, as well as more accurate formulas which can be used for design purposes. There are promising applications of these principles to the design of fixed-field synchrotrons, betatrons, and high-energy cyclotrons.« less

  5. Proton-Proton Scattering at 437 Mev

    Sutton, R. B. ; Fields, T. H. ; Fox, J. G. ; ... - Physical Review
    This paper is a detailed account of measurements, already briefly reported, of the angular distribution of proton-proton scattering at 437 Mev. A description is given of the external proton beam: its collimation, angular spread, energy spectrum, and intensity. The counters, electronics, and targets are described. Two scattering arrangements were used. In one the polyethylene-carbon subtraction method with coincidence detection of the scattered and recoil protons was employed. In the other a counter telescope detected the protons emerging at a given angle from a liquid hydrogen target; at the larger angles but not at the smaller the scattered pairs could alsomore » be detected by coincidences between the telescope and another counter. At the smaller angles, when coincidence counting could not be used to insure detection of elastic p – p scattering, precautions were taken to absorb the particles produced in inelastic p – p collisions. Finally, the results are that the differential cross section for elastic proton-proton scattering rises smoothly from its value at 90° c.m. to a value about 20 percent higher at 17° c.m. The value at 90° c.m. is 3.49 ± 0.17 mb/sterad.« less

  6. The Attenuation Cross Sections of 37-Mev Pions in Hydrogen

    Angell, C. E. ; Perry, J. P. - Physical Review
    We previously reported 16.0±1.0 millibarns for the attenuation cross section of 37-Mev positive pions and 17.3±1.4 millibarns, for negative pions in hydrogen. Here we discuss an important correction.

  7. The Total Cross Sections of Positive Pions in Hydrogen

    Barnes, S. W. ; Clark, D. L. ; Perry, J. P. ; ... - Physical Review
    In this work, the total cross sections of positive pions in hydrogen have been measured for pion energies of 56 Mev and above. Here we report a similar, though preliminary, measurement made at a mean energy of 37 Mev.

  8. On Deflection at n = 1 in the Synchrocyclotron

    Hamilton, Donald R. ; Lipkin, Harry J. - Review of Scientific Instruments
    Herein this paper discusses the theory of a possible method of synchrocyclotron beam deflection in which the orbits expand until the point of maximum Hr(n=1) is reached, after which the ions escape and spiral outward. These spirals should have a uniform starting radius and a small pitch in order to give deflection efficiency of the order of 100 percent; it is shown that this requires a flat maximum of Hr at n=1, and small amplitude of radial oscillation. The radial and vertical oscillations of the beam and the couplings thereof are discussed in detail. It appears that the only fieldmore » inhomogeneities which must be carefully minimized are those at n=1 and n=0. Limits on radial and vertical oscillations in the immediate vicinity of the ion source are set but the origins thereof in phenomena other than field inhomogeneity are not discussed.« less

  9. The Polarization of Sodium Atoms

    Hawkins, W. B. ; Dicke, R. H. - Physical Review
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