4,877 research outputs found
Particle-Antiparticle Asymmetries of Production in Hadron-Nucleon Collisions
The particle-antiparticle asymmetries of production in 250 GeV/c
, , and --nucleon collisions are studied with two model
parametrizations of quark to 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 beams, and high precision measurements of the
asymmetries with detailed and 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
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
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
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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