3,277 research outputs found

    Hamara Healthy Living Centre - an evaluation

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    Hamara is a Healthy Living Centre which aims to improve health and well-being through providing a range of culturally appropriate activities and services. Hamara has a vision of 'bringing communities together' and since it was established in 2004, the Centre has provided a valuable community resource in South Leeds. Partnership work between Hamara and Leeds Met goes back to 2002. In 2007, the Centre for Health Promotion Research carried out an evaluation of Hamara in partnership with Hamara staff and Leeds Met Community Partnerships and Volunteering. This was followed by a highly successful community cohesion conference 'One Community' which was held at Hamara on 10th October 2008, and was supported through a Leeds Met public engagement grant. The event attracted over a hundred people from diverse communities and organisations across Leeds. A packed audience heard Hilary Benn, local MP and Patron of Hamara, talk about the importance of working in collaboration around community cohesion. Jane South, Centre for Health Promotion Research, presented the main evaluation results and set out the some challenges for the future. The proceedings concluded with the presentation of awards to a number of for local community champions who work to bring people together and make a real difference in the city of Leeds

    Experiments to Find or Exclude a Long-Lived, Light Gluino

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    Gluinos in the mass range ~1 1/2 - 3 1/2 GeV are absolutely excluded. Lighter gluinos are allowed, except for certain ranges of lifetime. Only small parts of the mass-lifetime parameter space are excluded for larger masses unless the lifetime is shorter than ~ 2 10^{-11} (m_{gluino}/ GeV) sec. Refined mass and lifetime estimates for R-hadrons are given, present direct and indirect experimental constraints are reviewed, and experiments to find or definitively exclude these possibilities are suggested.Comment: 27 pp, latex with 1 uufiled figure, RU-94-35. New version amplifies discussion of some points and corresponds to version for Phys. Rev.

    Recalculation of Proton Compton Scattering in Perturbative QCD

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    At very high energy and wide angles, Compton scattering on the proton (gamma p -> gamma p) is described by perturbative QCD. The perturbative QCD calculation has been performed several times previously, at leading twist and at leading order in alpha_s, with mutually inconsistent results, even when the same light-cone distribution amplitudes have been employed. We have recalculated the helicity amplitudes for this process, using contour deformations to evaluate the singular integrals over the light-cone momentum fractions. We do not obtain complete agreement with any previous result. Our results are closest to those of the most recent previous computation, differing significantly for just one of the three independent helicity amplitudes, and only for backward scattering angles. We present results for the unpolarized cross section, and for three different polarization asymmetries. We compare the perturbative QCD predictions for these observables with those of the handbag and diquark models. In order to reduce uncertainties associated with alpha_s and the three-quark wave function normalization, we have normalized the Compton cross section using the proton elastic form factor. The theoretical predictions for this ratio are about an order of magnitude below existing experimental data.Comment: Latex, 23 pages, 13 figures. Checked numerical integration one more way; added results for one more proton distribution amplitude; a few other minor changes. Version to appear in Phys. Rev.

    Wide-angle elastic scattering and color randomization

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    Baryon-baryon elastic scattering is considered in the independent scattering (Landshoff) mechanism. It is suggested that for scattering at moderate energies, direct and interchange quark channels contribute with equal color coefficients because the quark color is randomized by soft gluon exchange during the hadronization stage. With this assumption, it is shown that the ratio of cross sections Rpp/ppR_{\overline{p} p/ p p} at CM angle θ=900\theta = 90^0 decreases from a high energy value of R_{\pbar p / pp} \approx 1/2.7, down to R_{\pbar p / pp} \approx 1/28, compatible with experimental data at moderate energies. This sizable fall in the ratio seems to be characteristic of the Landshoff mechanism, in which changes at the quark level have a strong effect precisely because the hadronic process occurs via multiple quark scatterings. The effect of color randomization on the angular distribution of proton-proton elastic scattering and the cross section ratio Rnp/ppR_{np/pp} is also discussed.Comment: 18 pages, latex2e, 4 uuencoded figures, include

    Electroproduction and Hadroproduction of Light Gluinos

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    In a class of supergravity models, the gluino and photino are massless at tree level and receive small masses through radiative corrections. In such models, one expects a gluino-gluon bound state, the R0R_0, to have a mass of between 1.0 and 2.2 GeV and a lifetime between 101010^{-10} and 10610^{-6} seconds. Applying peturbative QCD methods (whose validity we discuss), we calculate the production cross sections of R0R_0's in epe-p, πp\pi-p, KpK-p, pp\overline{p}-p and ppp-p collisions. Signatures are also discussed.Comment: 10 pages, latex, 6 figures uuencoded, figures also available via anonymous ftp to ftp://physics.wm.edu/pub/gluinofig.p

    Lattice Calculation of Point-to-Point Hadron Current Correlation

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    Point-to-point correlation functions of hadron currents in the QCD vacuum are calculated on a lattice and analyzed using dispersion relations, providing physical information down to small spatial separations. Qualitative agreement with phenomenological results is obtained in channels for which experimental data are available, and these correlation functions are shown to be useful in exploring approximations based on sum rules and interacting instantons.Comment: 11 page

    J/\Psi production, χ\chi polarization and Color Fluctuations

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    The hard contributions to the heavy quarkonium-nucleon cross sections are calculated based on the QCD factorization theorem and the nonrelativistic quarkonium model. We evaluate the nonperturbative part of these cross sections which dominates at sNN20\sqrt{s_{NN}}\approx 20 GeV at the Cern Super Proton Synchrotron (SPS) and becomes a correction at sNN6\sqrt{s_{NN}}\approx 6 TeV at the CERN Large Hadron Collider (LHC). \J production at the CERN SPS is well described by hard QCD, when the larger absorption cross sections of the χ\chi states predicted by QCD are taken into account. We predict an AA-dependent polarization of the χ\chi states. The expansion of small wave packets is discussed.Comment: 13 pages REVTEX, 1 table, 2 PostScript, corrected some typo

    Correlation between Compact Radio Quasars and Ultra-High Energy Cosmic Rays

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    Some proposals to account for the highest energy cosmic rays predict that they should point to their sources. We study the five highest energy events (E>10^20 eV) and find they are all aligned with compact, radio-loud quasars. The probability that these alignments are coincidental is 0.005, given the accuracy of the position measurements and the rarity of such sources. The source quasars have redshifts between 0.3 and 2.2. If the correlation pointed out here is confirmed by further data, the primary must be a new hadron or one produced by a novel mechanism.Comment: 8 pages, 3 tables, revtex. with some versions of latex it's necessary to break out the tables and latex them separately using article.sty rather than revtex.st

    Upper bounds on all R-parity-violating \lambda\lambda'' combinations from proton stability

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    In an R-parity-violating supersymmetric theory, we derive upper bounds on all the \lambda''_{ijk}\lambda_{i'j'k'}-type combinations from the consideration of proton stability, where \lambda''_{ijk} are baryon-number-violating couplings involving three baryonic fields and \lambda_{i'j'k'} are lepton-number-violating couplings involving three leptonic fields.Comment: 5 pages, Latex, uses axodraw.sty; minor changes in the text. Final versio
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