7 research outputs found
QCD at small x and nucleus-nucleus collisions
At large collision energy sqrt(s) and relatively low momentum transfer Q, one
expects a new regime of Quantum Chromo-Dynamics (QCD) known as "saturation".
This kinematical range is characterized by a very large occupation number for
gluons inside hadrons and nuclei; this is the region where higher twist
contributions are as large as the leading twist contributions incorporated in
collinear factorization. In this talk, I discuss the onset of and dynamics in
the saturation regime, some of its experimental signatures, and its
implications for the early stages of Heavy Ion Collisions.Comment: Plenary talk given at QM2006, Shanghai, November 2006. 8 pages, 8
figure
Thermal Dileptons at LHC
We predict dilepton invariant-mass spectra for central 5.5 ATeV Pb-Pb
collisions at LHC. Hadronic emission in the low-mass region is calculated using
in-medium spectral functions of light vector mesons within hadronic many-body
theory. In the intermediate-mass region thermal radiation from the Quark-Gluon
Plasma, evaluated perturbatively with hard-thermal loop corrections, takes
over. An important source over the entire mass range are decays of correlated
open-charm hadrons, rendering the nuclear modification of charm and bottom
spectra a critical ingredient.Comment: 2 pages, 2 figures, contributed to Workshop on Heavy Ion Collisions
at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May - 8 Jun
2007 v2: acknowledgment include
On the Equivalence of Reggeon Field Theory in Zero Transverse Dimensions and Reaction-Diffusion Processes.
The Reggeon field theory in zero transverse dimensions is investigated. Two
versions of the theory are considered: one that allows at most triple pomeron
interactions and the other that embodies an additional 2-->2 quartic Reggeon
coupling. The behavior of the scattering amplitude at asymptotic rapidities is
obtained in both cases. In an s-channel picture of the high energy scattering
both models can be viewed as reaction-diffusion processes. We derive known
results in Reggeon field theory rather easily using the reaction-diffusion
formalism. We find that some results which are surprising from the Reggeon
field theory point of view turn out to have a simple interpretation from the
reaction-diffusion point of view.Comment: 19 pages, no figure
Heavy-ion collisions at the LHC - Last call for predictions
This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last Call for Predictions', held from 14th May to 10th June 2007.This is a manuscript of an article from Journal of Physics G 35 (2008): 054001, doi: 10.1088/0954-3899/35/5/054001. Posted with permission.</p