1,345 research outputs found
Asymmetry studies in Lambda 0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ production
We present a study on hyperon/anti-hyperon production asymmetries in the
framework of the recombination model. The production asymmetries for Lambda
0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ are studied as a function of x_F.
Predictions of the model are compared to preliminary data on
hyperon/anti-hyperon production asymmetries in 500 GeV/c pi- p interactions
from the Fermilab E791 experiment. The model predicts a growing asymmetry with
the number of valence quarks shared by the target and the produced hyperons in
the x_F < 0 region. In the positive x_F region, the model predicts constant
asymmetries for Lambda 0/Lambda 0-bar and Omega-/Omega+ production and a
growing asymmetry with x_F for Xi-/Xi+. We found a qualitatively good agreement
between the model predictions and data, showing that recombination is a
competitive mechanism in the hadronization process.Comment: One reference correcte
Collisional parton energy loss in a finite size QCD medium revisited: Off mass-shell effects
We study the collisional energy loss mechanism for particles produced off
mass-shell in a finite size QCD medium. The off mass-shell effects introduced
are to consider particles produced in wave packets instead of plane waves and
the length scale associated to an in-medium particles' life-time. We show that
these effects reduce the energy loss as compared to the case when the particles
are described as freely propagating from the source. The reduction of the
energy loss is stronger as this scale becomes of the order or smaller than the
medium size. We discuss possible consequences of the result on the description
of the energy loss process in the parton recombination scenario.Comment: 9 pages, 4 figures. Enlarged discussion. References added. Version to
appear in Phys. Rev.
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