141 research outputs found

    Eritrocytic Parameters of the Blood of Calves with Different Birth Weights

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    In the conditions of a dairy farm with the help of the standard clinical, instrumental and laboratory methods the research on particularities of Eritrocytic parameters of the blood of calves (n=299) with different birth weights was carried out. It is shown that Holstein calves with normal intrauterine growth, born with body weight from 36.5 to 29 kg, have no reliable differences in red blood cell count. With a 1 kg reduction in body weight, there is a trend towards hyperchromia, but an increase in weight deficiency promotes of hypovolemia, hypochromia, and polycythaemia. In newborns with a body weight of 27.9–26.9 kg, polycythaemia is derived from hypovolemia, but, with a more pronounced weight deficiency, the role of erythrogenesis disorder in the pathogenesis of the syndrome increases. Hypochromia is a consequence of hematopoietic organs dysfunction and transmembrane loss of hemoglobin. Herein membrane destruction is caused by the increase in the content of toxical metabolites in the blood (sorptivity of red blood cells by 10–12 percent), and by a higher level of adrenaline (modification coefficient of membranes by adrenaline by 20–30 %). This indicates that the response of the fetus to the factors that inhibit its development is similar to a metabolic response against stress. At strong underweight body (b.w. less than 25 kg) exhausting of adaptive capability is observed with the increase in the blood level of toxical metabolites (sorptivity of red blood cells by 15 %), level of membrane destruction (level of ectoglobular hemoglobin in 2,8 times), and heterogeneity of red blood cells. Thus, in newborns with a body weight of less than 29 kg, the significant disturbances in the structure and functions of red blood cells were revealed, which gave grounds for stating that they had antenatal hypotrophy. Herewith, the severity of hematological changes depends on the degree of weight deficiency. Initially, it is hypovolemia and the resulting polycythemia, but, erythropoiesis disorders, and destruction of their membranes with increased polycythemia, and the development of hypochromia occur with the increasing severity of hypotrophy

    What did HERA teach us about the structure of the proton?

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    Starting in 2008 the H1 and ZEUS experiments have been combining their data in order to provide the most complete and accurate set of deep-inelastic data as the legacy of HERA. The present review presents these combinations, both published and preliminary, and explores how they have been used to give information on the structure of the proton. The HERAPDF parton distribution functions (PDFs) are presented and compared with other current PDFs and with data from the Tevatron and LHC colliders.Comment: 49 pages, 49 figures, to be published in J.Phys.

    Uncertainties on parton distribution functions from the ZEUS NLO QCD fit to data on deep inelastic scattering

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    An NLO QCD analysis of the ZEUS data on e+pe^+ p deep inelastic scattering together with fixed-target data has been performed from which the gluon and quark densities of the proton and the value of the strong coupling parameter, αs(MZ2)\alpha_s(M_Z^2), have been extracted. The study includes a full treatment of the experimental systematic uncertainties, including point-to-point correlations. Different ways of incorporating correlated systematic uncertainties into the fit are discussed and compared.Comment: 8 pages, 1 figure. Invited talk at the Conference on Advanced Statistical Techniques in Particle Physics, March 18-22 2002, Durham, U

    Isospin Dependence of Power Corrections in Deep Inelastic Scattering

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    We present results of a perturbative QCD analysis of deep inelastic measurements of both the deuteron and proton structure functions. We evaluate the theoretical uncertainty associated to nuclear effects in the deuteron, and we extract simultaneously the isospin depedendence of: i)the higher twists terms; ii) the ratio of the longitudinal to transverse cross sections; iii) the ratio of the neutron to proton structure functions. The extraction of the latter, in particular, has been at the center of an intense debate. Its accurate determination is crucial both theoretically and for the interpretation of the more precise neutrino experiments including the newly planned high intensity 50 GeV proton synchrotron.Comment: 33 pages, 16 figure

    A Precise Measurement of the Muon Neutrino-Nucleon Inclusive Charged Current Cross-Section off an Isoscalar Target in the Energy Range 2.5 < E_\nu < 40 GeV by NOMAD

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    We present a measurement of the muon neutrino-nucleon inclusive charged current cross-section, off an isoscalar target, in the neutrino energy range 2.5Eν402.5 \leq E_\nu \leq 40 GeV. The significance of this measurement is its precision, ±4\pm 4% in 2.5Eν102.5 \leq E_\nu \leq 10 GeV, and ±2.6\pm 2.6% in 10Eν4010 \leq E_\nu \leq 40 GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.Comment: 14 pages, 3 figures, submitted to Phys.Lett.

    A Study of Strange Particles Produced in Neutrino Neutral Current Interactions in the NOMAD Experiment

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    Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles (K0s, Lambda, Lambda-bar) have been measured. Decays of resonances and heavy hyperons with an identified K0s or Lambda in the final state have been analyzed. Clear signals corresponding to K* and Sigma(1385) have been observed. First results on the measurements of the Lambda polarization in neutral current interactions have been obtained.Comment: Accepted for publication in Nuclear Physics B as a rapid communicatio

    A Measurement of Coherent Neutral Pion Production in Neutrino Neutral Current Interactions in NOMAD

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    We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to 1.44×1061.44 \times 10^6 muon-neutrino Charged Current interactions in the energy range 2.5Eν3002.5 \leq E_{\nu} \leq 300 GeV. Neutrino events with only one visible π0\pi^0 in the final state are expected to result from two Neutral Current processes: coherent π0\pi^0 production, {\boldmath ν+Aν+A+π0\nu + {\cal A} \to \nu + {\cal A} + \pi^0} and single π0\pi^0 production in neutrino-nucleon scattering. The signature of coherent π0\pi^0 production is an emergent π0\pi^0 almost collinear with the incident neutrino while π0\pi^0's produced in neutrino-nucleon deep inelastic scattering have larger transverse momenta. In this analysis all relevant backgrounds to the coherent π0\pi^0 production signal are measured using data themselves. Having determined the backgrounds, and using the Rein-Sehgal model for the coherent π0\pi^0 production to compute the detection efficiency, we obtain {\boldmath 4630±522(stat)±426(syst)4630 \pm 522 (stat) \pm 426 (syst)} corrected coherent-π0\pi^0 events with Eπ00.5E_{\pi^0} \geq 0.5 GeV. We measure {\boldmath σ(νAνAπ0)=[72.6±8.1(stat)±6.9(syst)]×1040cm2/nucleus\sigma (\nu {\cal A} \to \nu {\cal A} \pi^0) = [ 72.6 \pm 8.1(stat) \pm 6.9(syst) ] \times 10^{-40} cm^2/nucleus}. This is the most precise measurement of the coherent π0\pi^0 production to date.Comment: 23 pages, 9 figures, accepted for publication in Phys. Lett.

    Hard Interactions of Quarks and Gluons: a Primer for LHC Physics

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    In this review article, we develop the perturbative framework for the calculation of hard scattering processes. We undertake to provide both a reasonably rigorous development of the formalism of hard scattering of quarks and gluons as well as an intuitive understanding of the physics behind the scattering. We emphasize the importance of logarithmic corrections as well as power counting of the strong coupling constant in order to understand the behavior of hard scattering processes. We include "rules of thumb" as well as "official recommendations", and where possible seek to dispel some myths. Experiences that have been gained at the Fermilab Tevatron are recounted and, where appropriate, extrapolated to the LHC.Comment: 118 pages, 107 figures; to be published in Reports on Progress in Physic

    Measurement of three-jet differential cross sections d sigma-3jet / d M-3jet in p anti-p collisions at sqrt(s)=1.96 TeV

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    We present the first measurement of the inclusive three-jet differential cross section as a function of the invariant mass of the three jets with the largest transverse momenta in an event in p anti-p collisions at sqrt(s) = 1.96 TeV. The measurement is made in different rapidity regions and for different jet transverse momentum requirements and is based on a data set corresponding to an integrated luminosity of 0.7 fb^{-1} collected with the D0 detector at the Fermilab Tevatron Collider. The results are used to test the three-jet matrix elements in perturbative QCD calculations at next-to-leading order in the strong coupling constant. The data allow discrimination between parametrizations of the parton distribution functions of the proton.Comment: 10 pages, 4 figures, 2 tables, submitted to Phys. Lett. B, corrected chi2 values for NNPD
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