9,449 research outputs found
Vector potential versus colour charge density in low-x evolution
We reconsider the evolution equations for multigluon correlators derived in
hep-ph/9709432. We show how to derive these equations directly in terms of
vector potentials (or colour field strength) avoiding the introduction of the
concept of colour charge density in the intermediate steps. The two step
procedure of deriving the evolution of the charge density correlators followed
by the solution of classical equations for the vector potentials is shown to be
consistent with direct derivation of evolution for vector potentials. In the
process we correct some computational errors of hep-ph/9709432 and present the
corrected evolution equations which have a somewhat simpler appearance.Comment: 15 pages, 1 figure, changes made referee report, to be published in
Phys. Rev
Saturation physics and angular correlations at RHIC and LHC
We investigate the angular correlation between pions and photons produced in
deuteron-gold collisions at RHIC and proton-lead collisions at LHC using the
Color Glass Condensate formalism and make predictions for the dependence of the
production cross section on the angle between the pion and photon at different
rapidities and transverse momenta. Measuring this dependence would shed further
light on the role of high gluon density and saturation dynamics at RHIC and
LHC.Comment: 2-column EPJ C format, requires svjour.cls and svepj.clo; 4 pages, 4
figure
Assessing, valuing and protecting our environment- is there a statistical challenge to be answered?
This short article describes some of the evolution in environmental regulation, management and monitoring and the information needs, closely aligned to the statistical challenges to deliver the evidence base for change and effect
Nanovoid nucleation by vacancy aggregation and vacancy-cluster coarsening in high-purity metallic single crystals
A numerical model to estimate critical times required for nanovoid nucleation in high-purity aluminum single crystals subjected to shock loading is presented. We regard a nanovoid to be nucleated when it attains a size sufficient for subsequent growth by dislocation-mediated plasticity. Nucleation is assumed to proceed by means of diffusion-mediated vacancy aggregation and subsequent vacancy cluster coarsening. Nucleation times are computed by a combination of lattice kinetic Monte Carlo simulations and simple estimates of nanovoid cavitation pressures and vacancy concentrations. The domain of validity of the model is established by considering rate-limiting physical processes and theoretical strength limits. The computed nucleation times are compared to experiments suggesting that vacancy aggregation and cluster coarsening are feasible mechanisms of nanovoid nucleation in a specific subdomain of the pressure-strain rate-temperature space
Shadowing of gluons in perturbative QCD: A comparison of different models
We investigate the different perturbative QCD-based models for nuclear
shadowing of gluons. We show that in the kinematic region appropriate to RHIC
experiment, all models give similar estimates for the magnitude of gluon
shadowing. At scales relevant to LHC, there is a sizable difference between
predictions of the different models.Comment: 11 pages, 4 figure
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