3,157 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
Two-way interplays between capital buffers, credit and output: evidence from French banks
We assess the extent to which capital buffers (the capital banks hold in excess of the regulatory minimum) exacerbate rather than reduce the cyclical behavior of credit. We empirically study the relationships between output gap, capital buffers and loan growth with firm-level data for French banks over the period 1993â2009. Our findings reveal that bank capital buffers intensify the cyclical credit fluctuations arising from the output gap developments, all the more as better quality capital is considered. Moreover, by performing Granger causality tests at the bank level, we find evidence of a two-way causality between capital buffers and loan growth, pointing to mutually reinforcing mechanisms. Overall, those empirical results lend support to a countercyclical financial regulation that focuses on highest-quality capital and aims at smoothing loan growth.Bank Capital Regulation, Procyclicality, Capital Buffers, Business Cycle Fluctuations, Basel III.
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.
Predictions for p+Pb at 4.4A TeV to Test Initial State Nuclear Shadowing at energies available at the CERN Large Hadron Collider
Collinear factorized perturbative QCD model predictions are compared for p+Pb
at 4.4A TeV to test nuclear shadowing of parton distribution at the Large
Hadron Collider (LHC). The nuclear modification factor (NMF),
R_{pPb}(y=0,p_T<20 GeV/c) = dn_{p Pb} /(N_{coll}(b)dn_{pp}), is computed with
electron-nucleus (e+A) global fit with different nuclear shadow distributions
and compared to fixed Q^2 shadow ansatz used in Monte Carlo Heavy Ion Jet
Interacting Generator (HIJING) type models. Due to rapid DGLAP reduction of
shadowing with increasing Q^2 used in e+A global fit, our results confirm that
no significant initial state suppression is expected (R_{pPb} (p_T) = 1 \pm
0.1) in the p_T range 5 to 20 GeV/ c. In contrast, the fixed Q^2 shadowing
models assumed in HIJING type models predict in the above p_T range a sizable
suppression, R_{pPb} (p_T) = 0.6-0.7 at mid-pseudorapidity that is similar to
the color glass condensate (CGC) model predictions. For central (N_{coll} = 12)
p+ Pb collisions and at forward pseudorapidity (\eta = 6) the HIJING type
models predict smaller values of nuclear modification factors (R_{pPb}(p_T))
than in minimum bias events at mid-pseudorapidity (\eta = 0). Observation of
R_{pPb}(p_T= 5-20 GeV/c) less than 0.6 for minimum bias p+A collisions would
pose a serious difficulty for separating initial from final state interactions
in Pb+Pb collisions at LHC energies.Comment: Revised version accepted for publication; Phys. Rev. C, in press, 16
pages, 4 figures, text modifications, added references, new figure 4, revtex
- âŠ