101 research outputs found
Diffractive Dijet Production
We explore the diffractive interaction of a proton with an anti-proton which
results in centrally produced dijets. This process has been recently studied at
the Tevatron. We make predictions within an Ingelman-Schlein approach and
compare them to the recent data presented by the CDF collaboration. Earlier
calculations resulted in theoretical cross-sections which are much larger than
those observed by CDF. We find that, after consideration of hadronisation
effects and the parton shower, and using parton density functions extracted
from diffractive deep inelastic scattering at HERA, it is possible to explain
the CDF data. We need to assume a gap survival probability of around 10% and
this is in good agreement with the value predicted by theory. We also find that
the non-diffractive contribution to the process is probably significant in the
kinematical region probed by the Tevatron.Comment: 12 pages, 6 figures, 3 table
Cold Nuclear Matter Effects on Dijet Productions in Relativistic Heavy-ion Reactions at LHC
We investigate the cold nuclear matter(CNM) effects on dijet productions in
high-energy nuclear collisions at LHC with the next-to-leading order
perturbative QCD. The nuclear modifications for dijet angular distributions,
dijet invariant mass spectra, dijet transverse momentum spectra and dijet
momentum imbalance due to CNM effects are calculated by incorporating EPS, EKS,
HKN and DS param-etrization sets of parton distributions in nucleus . It is
found that dijet angular distributions and dijet momentum imbalance are
insensitive to the initial-state CNM effects and thus provide optimal tools to
study the final-state hot QGP effects such as jet quenching. On the other hand,
the invariant mass spectra and the transverse momentum spectra of dijet are
generally enhanced in a wide region of the invariant mass or transverse
momentum due to CNM effects with a feature opposite to the expected suppression
because of the final-state parton energy loss effect in the QGP. The difference
of EPS, EKS, HKN and DS parametrization sets of nuclear parton distribution
functions is appreciable for dijet invariant mass spectra and transverse
momentum spectra at p+Pb collisions, and becomes more pronounced for those at
Pb+Pb reactions.Comment: 10 pages, 11 figure
Avaliação de resĂduo de antibiĂłtico em amostras de leite de vacas apĂłs a terapia de vacas secas
Differential growth retardation and Myofibrillar fragmentation in rats submitted to feed restriction and realimentation
History of clinical transplantation
How transplantation came to be a clinical discipline can be pieced together by perusing two volumes of reminiscences collected by Paul I. Terasaki in 1991-1992 from many of the persons who were directly involved. One volume was devoted to the discovery of the major histocompatibility complex (MHC), with particular reference to the human leukocyte antigens (HLAs) that are widely used today for tissue matching.1 The other focused on milestones in the development of clinical transplantation.2 All the contributions described in both volumes can be traced back in one way or other to the demonstration in the mid-1940s by Peter Brian Medawar that the rejection of allografts is an immunological phenomenon.3,4 © 2008 Springer New York
Presença de formas amastigotas de Leishmania chagasi e perfil leucocitårio no aparelho reprodutivo de cães
Desempenho em confinamento de novilhos 5/8 Nelore - 3/8 CharolĂȘs abatidos em diferentes estĂĄdios de desenvolvimento
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