8 research outputs found

    Limits on Production of Magnetic Monopoles Utilizing Samples from the DO and CDF Detectors at the Tevatron

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    We present 90% confidence level limits on magnetic monopole production at the Fermilab Tevatron from three sets of samples obtained from the D0 and CDF detectors each exposed to a proton-antiproton luminosity of ∼175pb−1\sim175 {pb}^{-1} (experiment E-882). Limits are obtained for the production cross-sections and masses for low-mass accelerator-produced pointlike Dirac monopoles trapped and bound in material surrounding the D0 and CDF collision regions. In the absence of a complete quantum field theory of magnetic charge, we estimate these limits on the basis of a Drell-Yan model. These results (for magnetic charge values of 1, 2, 3, and 6 times the minimum Dirac charge) extend and improve previously published bounds.Comment: 18 pages, 17 figures, REVTeX

    Primordial Nucleosynthesis for the New Cosmology: Determining Uncertainties and Examining Concordance

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    Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) have a long history together in the standard cosmology. The general concordance between the predicted and observed light element abundances provides a direct probe of the universal baryon density. Recent CMB anisotropy measurements, particularly the observations performed by the WMAP satellite, examine this concordance by independently measuring the cosmic baryon density. Key to this test of concordance is a quantitative understanding of the uncertainties in the BBN light element abundance predictions. These uncertainties are dominated by systematic errors in nuclear cross sections. We critically analyze the cross section data, producing representations that describe this data and its uncertainties, taking into account the correlations among data, and explicitly treating the systematic errors between data sets. Using these updated nuclear inputs, we compute the new BBN abundance predictions, and quantitatively examine their concordance with observations. Depending on what deuterium observations are adopted, one gets the following constraints on the baryon density: OmegaBh^2=0.0229\pm0.0013 or OmegaBh^2 = 0.0216^{+0.0020}_{-0.0021} at 68% confidence, fixing N_{\nu,eff}=3.0. Concerns over systematics in helium and lithium observations limit the confidence constraints based on this data provide. With new nuclear cross section data, light element abundance observations and the ever increasing resolution of the CMB anisotropy, tighter constraints can be placed on nuclear and particle astrophysics. ABRIDGEDComment: 54 pages, 20 figures, 5 tables v2: reflects PRD version minor changes to text and reference

    Errata: In the article ‘Haulout site selection by southern elephant seals at Marion Island’ that appeared in

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    ErrataIn the article ‘Haulout site selection by southern elephant seals at Marion Island’ that appeared in African Zoology 43(1):25–33 (April 2008), the institutional affiliations of the authors should have read:T.W. Mulaudzi1*, G.J.G. Hofmeyr1, M.N. Bester1, S.P. Kirkman1, P.A. Pistorius1,F.C. Jonker1, A.B. Makhado1, J.H. Owen2 & R.J. Grimbeek21. Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, 0002 South Africa2. Department of Statistics, University of Pretoria, Pretoria, 0002 South Africa*Author for correspondence. Present address: National Zoological Gardens of South Africa, P.O. Box 754, Pretoria, 0002 South Africa.E-mail: [email protected]

    Haulout site selection by southern elephant seals at Marion Island

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    Using data from an ongoing mark–resight programme at Marion Island, we tested  empirically whether southern elephant seals prefer certain terrestrial sites to others during the breeding, moulting and winter haulouts, and whether the pattern of site use is the same for different age and sex groups. Southern elephant seals preferred some sites, while discriminating against other sites, with different age and sex classes using different sites for certain haulout events. Wintering young animals did not show strong site selection. Some popular sites were used for all haulouts by all age and sex groups, and apparently have all the requirements of a good site for terrestrial haulout by southern elephant seals. Site selection becomes more apparent with age, suggesting the role of haulout experience in site selection.Key words: southern elephant seal, Mirounga leonina, Marion Island, age group, haulout, site selection
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