558 research outputs found
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
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
From RHIC to EIC: Nuclear Structure Functions
We study the nuclear structure function and its logarithmic
derivative in the high energy limit (small region) using the Color Glass
Condensate formalism. In this limit the structure function depends on the
quark anti-quark dipole-target scattering cross section . The same dipole cross section appears in single hadron and hadron-photon
production cross sections in the forward rapidity region in deuteron
(proton)-nucleus collisions at high energy, i.e. at RHIC and LHC. We use a
parameterization of the dipole cross section, which has successfully been used
to describe the deuteron-gold data at RHIC, to compute the nuclear structure
function and its log derivative (which is related to gluon
distribution function in the double log limit). We provide a quantitative
estimate of the nuclear shadowing of and the gluon distribution
function in the kinematic region relevant to a future Electron-Ion Collider.Comment: 13 pages, 6 figure
Quark production in high energy proton-nucleus collisions
In this note, we discuss the problem of quark-antiquark pair production in
the framework of the color glass condensate. The cross-section can be
calculated in closed form for the case of proton-nucleus collisions, where the
proton can be considered to be a dilute object. We find that kt-factorization
is broken by rescattering effects.Comment: 6 pages, 3 figures, based on talks given at Hard Probes 2004 by H.
Fujii and F. Geli
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
The Color Glass Condensate: an overview
The Color Glass Condensate is a theory of the dynamical properties of partons
in the Regge limit of QCD: x_{\rm Bj}\to 0Q^2 >> \Lambda_{\rm QCD}^2={\rm
fixed} and the center of mass energy squared s\to \infty. We provide a brief
introduction to the theoretical ideas underlying the Color Glass Condensate and
discuss the application of these ideas to high energy scattering in QCD.Comment: 8 pages, Plenary talk at Hard Probes 2004, Ericeira, Portugal,
Nov.4th-10th, 200
Prompt photons at RHIC
We calculate the inclusive cross section for prompt photon production in
heavy-ion collisions at RHIC energies ( GeV and
GeV) in the central rapidity region including next-to-leading order,
, radiative corrections, initial state nuclear
shadowing and parton energy loss effects. We show that there is a significant
suppression of the nuclear cross section, up to at
GeV, due to shadowing and medium induced parton energy loss effects. We find
that the next-to-leading order contributions are large and have a strong
dependence.Comment: 9 pages, 5 figures, expanded discussion of the K facto
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