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Updated on June 8th 2007
Heavy Ion Collisions at the LHC
Last Call for Predictions
Monday May 14th to Friday June 8th 2007
The aim of this workshop, organized within the framework of the CERN Theory Institute, is to review and document the status of expectations and predictions for the heavy ion program at the LHC before its start. Analogous efforts prior to the start-up of RHIC proved very useful. They provided a natural forum for the exchange of the most recent ideas and helped to identify open questions. They also helped to distinguish pre- from post-dictions. This workshop aims at playing this role for the LHC. Participants may stay at CERN during part or the whole length of the workshop to prepare and discuss the predictions. Predictions from groups who may be unable to attend the workshop will be accepted for the publication, if they are received in writing prior to the start of the workshop.
Application is through the normal
CERN-TH visitor form
do not forget to specify that the purpose of your visit is "to participate in the CERN-TH institute on Predictions for HIC at the LHC".
In addition, please
send us an email
informing us about your application, with the dates you plan to attend. For submission of predictions for an oral presentation: please send an email to the convenor of the topical session indicating a title.
We plan to decide on the seminar structure of the workshop and on possible
financial support for participants by end of March 2007.
Written contributions to the workshop proceedings must be received before
the start of the workshop on Monday May 14th 2007.
(main, Universidade de Santiago de Compostela)
Urs Achim Wiedemann
(local, CERN PH-TH)
The proceedings will be published in Journal of Physics G. Each prediction should be summarized on at most two pages plus a few (< 5) references. Predictions should be presented, whenever possible, in figures which display measurable quantities. Each participant can summarize separately his predictions for each of the topics of the workshop. The workshop organizers are editors of the proceedings. They may solicit referee reports to determine whether contributions submitted are valid predictions. Also, significant editing of the received contributions is foreseen to turn them into a consistent document. However, this editing will not affect the content of contributions, and each contribution will be related clearly to its authors. Full model descriptions will not be accepted - the authors should just indicate the relevant references for the interested reader. For the format of the proceedings, please go to
and then click on the link "LaTeX guidelines and class file" which is in the yellow column on the left side of the web page. References must be included using the SPIRES key. Predictions neither orally presented during the focus week nor sent before its start will not be accepted.
J. Phys. G: Nucl. Part. Phys. 35 (2008) 054001
Depending on the availability of participants, we foresee to center part of the workshop activities in a focus week, with multiple oral presentations and discussions per day. We plan to hold this focus week in the week from
Tuesday May 29th to Saturday June 2nd 2007
The program will be organized into the following topical sessions:
Multiplicities and multiplicity distributions (convenor:
Azimuthal asymmetries (convenor:
Hadronic flavor observables (convenor:
Correlations at low transverse momentum (convenor:
High transverse momentum observables and jets (convenor:
Leptonic probes and photons (convenor:
The structure of the program will be decided depending on availability
On the basis of fund availability, participants will be supported by per diems from the budget of the CERN Theory Institute.
Setup for the predictions
In making predictions, participants are encouraged to focus on those systems tested first in heavy ion collisions at the LHC, namely Pb+Pb at 2.75+2.75 TeV per nucleon. Predictions for lighter systems, for p+A collisions and for the energy dependence of nucleus-nucleus collisions are also accepted, of course. For those, authors are encouraged to underline how such additional experiments can contribute to understand the physics of Pb+Pb collisions at full center of mass energy. For a common definition of centrality, we propose that central events are defined as the 10 percent more central ones. Kinematical cuts for the different detectors in the three experiments, ALICE, ATLAS and CMS, are provided below. We encourage the authors to use them in order to ease the comparison of their predictions with the forthcoming experimental data.
See enclosed document
Tracking (unidentified h+/-) [Tracker]
pi/K/p PID [Tracker]
Calorimetry (electrons, photons) [ECAL]
Calorimetry (jets) [ECAL-HCAL, HF]
Muons [Muon chambers]
Forward energy flow [T2, CASTOR]
Forward neutrons, photons [ZDC]
pT ~ 0.3 - 1000 GeV/c, |eta| < 2.5, full phi
pT ~ 0.3 - 1.5 GeV/c, |eta| < 2.5, full phi
pT ~ 4 - 1000 GeV/c, |eta| < 3, full phi
ET = 50 - 1000 GeV, |eta| < 5, full phi
p_T ~ 3.5 - 1000 GeV/c, |eta| < 2.5, full phi
5.3<~|eta|<~6.6, full phi
|eta| >~8.1, full phi