515 research outputs found
Baryon anomaly and strong color fields in Pb+Pb collisions at 2.76A TeV at the CERN Large Hadron Collider
With the HIJING/BBbar v2.0 heavy ion event generator, we explore the
phenomenological consequences of several high parton density dynamical effects
predicted in central Pb+Pb collisions at the Large Hadron Collider (LHC)
energies. These include (1) jet quenching due to parton energy loss (dE/dx),
(2) strangeness and hyperon enhancement due to strong longitudinal color field
(SCF), and (3) enhancement of baryon-to-meson ratios due to baryon-anti-baryon
junctions (JJbar) loops and SCF effects. The saturation/minijet cutoff scale
p0(s)and effective string tension kappa(s,A) are constrained by our previous
analysis of LHC p+p data and recent data on the charged multiplicity for Pb+Pb
collisions reported by the ALICE collaboration. We predict the hadron flavor
dependence (mesons and baryons) of the nuclear modification factor RAA(pT)$ and
emphasize the possibility that the baryon anomaly could persist at the LHC up
to pT=10 GeV, well beyond the range observed in central Au+Au collisions at
RHIC energies.Comment: 25 pages, 8 figures, revtex4, text modifications, added references,
accepted for publication Phys. Rev. C (2011
Soft Open Charm Production in Heavy-Ion Collisions
Effects of strong longitudinal color electric fields (SCF) on the open charm
production in nucleus-nucleus (A + A) collisions at 200A GeV are investigated
within the framework of the HIJING-BBbar v2.0 model. A three fold increase of
the effective string tension due to in medium effects in A + A collisions,
results in a sizeable (60-70 percents) enhancement of the total charm
production cross sections. The nuclear modification factors show a suppression
at moderate transverse momentum consistent with RHIC data. At Large Hadron
Collider energies the model predicts an increase of total charm production
cross sections by approximately an order of magnitude.Comment: 5 pages, 3 figures, submitted to Phys. Rev. Let
Strangeness Production in pp,pA,AA Interactions at SPS Energies.HIJING Approach
In this report we have made a systematic study of strangeness production in
proton-proton(pp),proton-nucleus(pA) and nucleus- nucleus(AA) collisions at
CERN Super Proton Synchroton energies, using \\ (version ). Numerical results for mean
multiplicities of neutral strange particles ,as well as their ratios to
negatives hadrons() for
p-p,nucleon-nucleon(N-N),\,\,p-S,\,\,p-Ag,\,\,p-Au('min. bias')collisions and
p-Au,\,\,S-S,\,\,S-Ag,\,\,S-Au ('central')collisions are compared to
experimental data available from CERN experiments and also with recent
theoretical estimations given by others models. Neutral strange particle
abundances are quite well described for p-p,N-N and p-A interactions ,but are
underpredicted by a factor of two in A-A interactions for
in symmetric collisions(S-S,\,\,Pb-Pb)and for
in asymmetric ones(S-Ag,\,\,S-Au,\,\,S-W). A
qualitative prediction for rapidity, transverse kinetic energy and transverse
momenta normalized distributions are performed at 200 GeV/Nucleon in
p-S,S-S,S-Ag and S-Au collisions in comparison with recent experimental data.
HIJING model predictions for coming experiments at CERN for S-Au, S-W and Pb-Pb
interactions are given. The theoretical calculations are estimated in a full
phase space.Comment: 33 pages(LATEX),18 figures not included,available in hard copy upon
request , Dipartamento di Fisica Padova,report DFPD-94-NP-4
Reply to Comment of Gazdzicki and Heinz on Strangeness Enhancement in and
The Comment of Gazdzicki and Heinz is flawed because their assumed baryon
stopping power in is inconsistent with data and because they ignored half
the analysis based on the VENUS model. The Comment continues the misleading
presentation of strangeness enhancement by focusing on ratios of integrated
yields. Those ratios discard essential experimental information on the rapidity
dependence of produced and obscure discrepancies between different
data sets. Our conclusion remains that the NA35 minimum bias data on
indicate an anomalous enhancement of central
rapidity strangeness in few nucleon reactions that points to non-equilibrium
dynamics as responsible for strangeness enhancement in nuclear reactions.Comment: revtex file, 6 pages, submitted to Phys. Rev.
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