4,877 research outputs found

    Particle-Antiparticle Asymmetries of Λ\Lambda Production in Hadron-Nucleon Collisions

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    The particle-antiparticle asymmetries of Λ\Lambda production in 250 GeV/c π±\pi^{\pm}, K±K^{\pm}, and pp --nucleon collisions are studied with two model parametrizations of quark to Λ\Lambda fragmentation functions. It is shown that the available data can be qualitatively explained by the calculated results in both the quark-diquark model and a pQCD based analysis of fragmentation functions. The differences in the two model predictions are significant for K±K^{\pm} beams, and high precision measurements of the asymmetries with detailed xFx_F and PTP_T information can discriminate between different predictions.Comment: 14 LaTex pages, 4 figures, to appear in Phys. Lett.

    Quark initiated coherent diffractive production of muon pair and W boson at hadron colliders

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    The large transverse momentum muon pair and W boson productions in the quark initiated coherent diffractive processes at hadron colliders are discussed under the framework of the two-gluon exchange parametrization of the Pomeron model. In this approach, the production cross sections are related to the small-x off-diagonal gluon distribution and the large-x quark distribution in the proton (antiproton). By approximating the off-diagonal gluon distribution by the usual gluon distribution function, we estimate the production rates of these processes at the Fermilab Tevatron.Comment: 11pages, 6 PS figures, to appear in PR

    Diffractive light quark jet production at hadron colliders in the two-gluon exchange model

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    Massless quark and antiquark jet production at large transverse momentum in the coherent diffractive processes at hadron colliders is calculated in the two-gluon exchange parametrization of the Pomeron model. We use the helicity amplitude method to calculate the cross section formula. We find that for the light quark jet production the diffractive process is related to the differential off-diagonal gluon distribution function in the proton. We estimate the production rate for this process at the Fermilab Tevatron by approximating the off-diagonal gluon distribution function by the usual diagonal gluon distribution in the proton. And we find that the cross sections for the diffractive light quark jet production and the charm quark jet production are in the same order of magnitude. We also use the helicity amplitude method to calculate the diffractive charm jet production at hadron colliders, by which we reproduce the leading logarithmic approximation result of this process we previously calculated.Comment: 15 pages, 4 PS figures, Revte

    Elucidating how the saprophytic fungus Aspergillus nidulans uses the plant polyester suberin as carbon source

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    Lipid polymers in plant cell walls, such as cutin and suberin, build recalcitrant hydrophobic protective barriers. Their degradation is of foremost importance for both plant pathogenic and saprophytic fungi. Regardless of numerous reports on fungal degradation of emulsified fatty acids or cutin, and on fungi-plant interactions, the pathways involved in the degradation and utilisation of suberin remain largely overlooked. As a structural component of the plant cell wall, suberin isolation, in general, uses harsh depolymerisation methods that destroy its macromolecular structure. We recently overcame this limitation isolating suberin macromolecules in a near-native state.work partially supported by a grant from Iceland, Liechtenstein and Norway through the EEA financial mechanism (Project PT015), FCT: grant (PEst-OE/EQB/LA0004/2013) and fellowships (SFRH/BD/38378/2007, SFRH/BD/66396/2009, SFRH/BD/66030/2009, SFRH/BD/48286/2008), Fundação Calouste Gulbenkian fellowship (21-95587-B)
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