11,684,014 research outputs found

    Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388

    Collins effect and single spin azimuthal asymmetries in the HERMES and COMPASS experiments

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    Predictions are made for single spin azimuthal asymmetries due to the Collins effect in pion production from semi-inclusive deeply inelastic scattering off transversely and longitudinally polarized targets for the HERMES and COMPASS experiments. The x-dependence of the asymmetries is evaluated using the parton distribution functions from the chiral quark-soliton model. The overall normalization of the predicted asymmetries is determined by the information on the Collins fragmentation function extracted from previous HERMES data on azimuthal asymmetries from a longitudinally polarized target. The single spin asymmetries from the transversely polarized proton target are found to be about 20% for positive and neutral pions both at HERMES and COMPASS. For a longitudinally polarized target we obtain for COMPASS a sin(phi) asymmetry of 1% and a sin(2phi) asymmetry of about 3%.Comment: 10 pages, 9 figures, Ref.[29] adde

    Measurement of the LT-asymmetry in \pi^0 electroproduction at the energy of the \Delta (1232) resonance

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    The reaction p(e,e'p)pi^0 has been studied at Q^2=0.2 (GeV/c)^2 in the region of W=1232 MeV. From measurements left and right of q, cross section asymmetries \rho_LT have been obtained in forward kinematics \rho_LT(\theta_\pi^0=20deg) = (-11.68 +/- 2.36_stat +/- 2.36_sys)$ and backward kinematics \rho_LT(\theta_\pi^0=160deg) =(12.18 +/- 0.27_stat +/- 0.82_sys). Multipole ratios \Re(S_1+^* M_1+)/|M_1+|^2 and \Re(S_0+^* M_1+)/|M_1+|^2 were determined in the framework of the MAID2003 model. The results are in agreement with older data. The unusally strong negative \Re(S_0+^* M_1+)/|M_1+|^2 required to bring also the result of Kalleicher et al. in accordance with the rest of the data is almost excluded.Comment: 7 pages, 7 figures, 4 tables. Changed content. Accepted for publication in EPJ

    Environmental problems and opportunities of the peri-urban interface and their impact upon the poor

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    The objective of this document is to provide an overview of the problems and opportunities of the peri-urban interface (PUI) with regard to the broad concerns of environmentalsustainability and poverty

    The importance of keeping regular: accurate guidance to the public on low-risk drinking levels

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    Aim The aim of this study was to argue that recommendations to the general public on daily amounts for low-risk alcohol consumption must retain the word ‘regular’ in order to avoid being rejected. Method Narrative review of the evidence-base for daily limits to alcohol consumption, the guidance the public actually receives in the UK and media reactions to this guidance. Results Evidence for daily limits (not more than 3–4 units for men and 2–3 units for women) rests on epidemiological surveys that enquire about ‘average’ or ‘usual’ amounts of consumption and this is reflected by the use of ‘regular’ or ‘consistent’ in the UK Government's Sensible Drinking report in 1995 and in guidance currently issued by the English Department of Health. In contrast, guidance the public actually receives often omits the word ‘regular’ and implies that the limits in question are maximum daily amounts. Media reactions to this inaccurate information suggest that the general public is likely to find these recommendations incredible and to reject them. Conclusion If guidance to the public on daily drinking amounts is to stand any chance of being credible and effective, it must be accurate and must therefore retain the word ‘regular’

    Generalized parton distributions from nucleon form factor data

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    We present a simple empirical parameterization of the x- and t-dependence of generalized parton distributions at zero skewness, using forward parton distributions as input. A fit to experimental data for the Dirac, Pauli and axial form factors of the nucleon allows us to discuss quantitatively the interplay between longitudinal and transverse partonic degrees of freedom in the nucleon ("nucleon tomography"). In particular we obtain the transverse distribution of valence quarks at given momentum fraction x. We calculate various moments of the distributions, including the form factors that appear in the handbag approximation to wide-angle Compton scattering. This allows us to estimate the minimal momentum transfer required for reliable predictions in that approach to be around |t|~3 GeV^2. We also evaluate the valence contributions to the energy-momentum form factors entering Ji's sum rule.Comment: 69 pages, 36 figures. v2: small improvements in text and figures; references adde

    ARE LEFT HANDED SURGEONS LEFT OUT?

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    Being a left-handed surgeon, more specifically a left-handed ENT surgeon, presents a unique pattern of difficulties.This article is an overview of left-handedness and a personal account of the specific difficulties a left-handed ENT surgeon faces. 

    The Prefix of Prefixes: Francis Ponge's 'Le Pre' and La Fabrique du 'Pre'

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    1996-01-01

    Indeks Subjek Volume 37, Tahun 2017

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