Conveners
Initial State and Proton-Nucleus Collision Phenomena
- Matthew Lamont (BNL)
Initial State and Proton-Nucleus Collision Phenomena
- Paul Stankus (Oak Ridge National Laboratory)
Initial State and Proton-Nucleus Collision Phenomena
- Alexander Kovner (University of Connecticut)
Initial State and Proton-Nucleus Collision Phenomena
- Sangyong Jeon (McGill University)
Initial State and Proton-Nucleus Collision Phenomena
- Peter Steinberg (Brookhaven National Laboratory)
Initial State and Proton-Nucleus Collision Phenomena
- Jorge Casalderrey-Solana (Universitat de Barcelona)
Description
Initial State and Proton-Nucleus Collision Phenomena
Dr
EDMOND IANCU
(IPhT, Saclay, CEA)
04/11/2013, 13:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
We study multi-particle production with rapidity correlations in proton-nucleus collisions at high energy in the Color Glass Condensate framework. The high-energy evolution responsible for such correlations is governed by a generalization of the JIMWLK equation describing the simultaneous evolution of the strong nuclear color fields in the direct amplitude and the complex conjugate amplitude....
Dr
Tuomas Lappi
(University of Jyväskylä)
04/11/2013, 13:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
In the CGC framework the initial stages of a heavy ion collision at high energy are described as "glasma" field configurations. The initial condition for these evolving fields depends, in the CGC effective theory, on a probability distribution for color charges. The energy dependence of this distribution can be calculated from the JIMWLK renormalization group equation.
We discuss recent...
Guillaume Beuf
(Universidade de Santiago de Compostela)
04/11/2013, 14:10
Initial State and Proton-Nucleus Collision Phenomena
Oral
Doga Gulhan
(Massachusetts Institute of Technology)
04/11/2013, 14:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
Results on dijet production in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV are presented. Jets are reconstructed with the anti-kT algorithm, using combined information from tracking and calorimetry. The dijet momentum balance, azimuthal angle correlations and pseudorapidity distributions are studied as a function of forward calorimeter transverse energy and compared...
Prof.
Mikhail Zavertyaev
(Max PLank Fuer Kernphysik, Heidelberg)
04/11/2013, 14:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
LHCb experiment performs multiple studies at 0.9TeV and 7TeV proton-proton interactions. Results on Energy flow, charge particle multiplicities, particle production ratios, charm production studies are presented and discussed. The comparison with the predictions of different models indicates that more efforts are needed for better understanding of physical processes.
Dr
J. Matthew Durham
(Los Alamos National Lab)
04/11/2013, 15:10
Initial State and Proton-Nucleus Collision Phenomena
Oral
It is becoming increasingly clear that initial state effects inherent to collisions of nuclei play an important role in the interpretation of data from heavy ion collisions at RHIC and the LHC. Such effects are more apparent in kinematic regions where the gluon density is expected to be significantly modified in the nucleus. The PHENIX experiment has studied these effects through the...
Dr
Paul Sorensen
(BNL)
04/11/2013, 16:00
Initial State and Proton-Nucleus Collision Phenomena
Oral
The azimuthal anisotropy of particle production is commonly used in high-energy nuclear collisions to study the early evolution of the expanding system. The prolate shape of uranium nuclei provides the possibility to study how the initial geometry of the nuclei affects the azimuthal distributions. It also provides a unique opportunity to understand the initial condition for particle production...
Krisztian Krajczar
(CERN)
04/11/2013, 16:20
Initial State and Proton-Nucleus Collision Phenomena
Oral
The charged particle transverse momentum (pT) spectra at midrapidity and forward pseudorapidity ranges up to pT=100 GeV/c are presented for pPb collisions at sqrt(sNN)=5.02 TeV. The nuclear modification factor (RpPb) is measured at midrapidity by dividing the measured pPb spectrum by a pp reference spectrum constructed using interpolation methods. In addition, the asymmetries in the charge...
Prof.
Rainer Fries
(Texas A&M University)
04/11/2013, 16:40
Initial State and Proton-Nucleus Collision Phenomena
Oral
We calculate the energy flow of the quasi-classical gluon field at early times in high energy nuclear collisions. We argue that the transverse flow has a rapidity-even component that is similar to collective flow in a fluid and emerges from the QCD analog of Farady's and Ampere's Law, and it has a rapidity-odd component that can be understood from Gauss' Law for gluon fields. While the former...
Mr
Thomas Epelbaum
(IPhT, CEA-Saclay)
04/11/2013, 17:00
Initial State and Proton-Nucleus Collision Phenomena
Oral
Real time lattice simulations of the early stages of high energy
collisions in the Color Glass Condensate framework indicate a rapid
isotropization of the pressure tensor. For realistic values of the
saturation momentum, nearly ideal hydrodynamics provides a good
description of the bulk evolution of the system after a transient
regime that lasts about 1 fermi/c.
Mr
Chun Shen
(The Ohio State University)
04/11/2013, 17:20
Initial State and Proton-Nucleus Collision Phenomena
Oral
As is well known, photons are a penetrating probe of the dense medium created in heavy-ion collisions. I will present state-of-the-art calculations of viscous photon emission from nuclear collisions at RHIC and LHC. Fluctuating initial density profiles are evolved with event-by-event viscous hydrodynamics. Momentum spectra of thermal photons radiated by these explosively expanding fireballs...
Dr
Jorge Casalderrey-Solana
(Universitat de Barcelona)
04/11/2013, 17:40
Initial State and Proton-Nucleus Collision Phenomena
Oral
We numerically simulate planar shock wave collisions in anti-de Sitter space as a model for heavy ion collisions of large nuclei. We uncover a cross-over between two different dynamical regimes as a function of the collision energy. At low energies the shocks first stop and then explode in a manner approximately described by hydrodynamics, in close similarity with the Landau model. At high...
Ms
Andrecia Ramnath
(University of Cape Town)
05/11/2013, 13:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
The Large Hadron Collider, located at the European Centre for Nuclear Research, is the most powerful particle collider ever built. The ATLAS experiment at the LHC uses the proton and heavy ion collisions produced in this 27 km long collider to probe the predictions and limitations of the Standard Model. Due to the high energies employed, collisions are able to probe a regime known as the...
Mr
Greg Jackson
(University of Cape Town)
05/11/2013, 13:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
We demonstrate measurable, falsifiable differences between the DGLAP and CGC predictions for the t-differential cross section of exclusive vector meson production (EVMP) in electron-ion collisions. These predictions permit an experimental determination of the dominant physical processes for low-x gluons in a high-energy nucleus. At eRHIC energies, J/psi photoproduction in e+A collisions...
Mr
Heikki Mäntysaari
(University of Jyväskylä)
05/11/2013, 14:10
Initial State and Proton-Nucleus Collision Phenomena
Oral
The Color Class Condensate offers a consistent framework to describe high-energy (small-x) data from various experiments. The non-perturbative input for these calculations, the dipole-target amplitude at initial Bjorken-x, is obtainable from electron-proton deep inelastic scattering processes. Once that is known, one can compute, for example, single and double inclusive particle production in...
Dr
Matthew Lamont
(BNL)
05/11/2013, 14:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
Despite the successes of the HERA collider, where much information was gained on the structure of the nucleon, data on the structure of the nucleus at moderate-to-small x remains elusive, as only fixed-target high-x data currently exist. The small-x region, however, is of great interest. The nucleon structure in this region is dominated by gluons which show a rapid rise with decreasing x. ...
Prof.
William Brooks
(Universidad Técnica Federico Santa María)
05/11/2013, 14:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
Our understanding of the structure of nucleons is described by the properties and dynamics of quarks and gluons in the theory of quantum chromodynamics. With advancements in theory and the development of phenomenological tools we are preparing for the next step in subnuclear tomographic imaging at a future electron-ion collider. High center-of-mass energies (up to 150 GeV) in combination with...
David d'Enterria
(CERN)
05/11/2013, 15:10
Initial State and Proton-Nucleus Collision Phenomena
Multi-parton scatterings are extremely enhanced in interactions involving nuclei at colliders, compared to proton-proton collisions at the same energy. We present the derivation of a simple generic expression to compute double-parton scattering (DPS) cross sections in high-energy proton-nucleus and nucleus-nucleus collisions as a function of the corresponding single-parton hard cross sections...
Dr
Chiara Oppedisano
(INFN, Torino, Italy)
07/11/2013, 13:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
Proton-nucleus collisions are studied to disentangle initial state effects,
already present in cold nuclear matter, from final state effects, expected only
when a dense and hot medium is formed as in A-A collisions.
The collisions can be characterized through the number of binary collisions the nucleons undergo. In p-Pb collisions, the low particle multiplicities
and the large multiplicity...
Prof.
Alexander Kovner
(University of Connecticut)
07/11/2013, 13:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
I describe several mechanisms that lead to ridge like correlations in the produced particle spectrum in p-p and p-A collisions at high energy. The discussion is within the Color Glass Condensate framework, but the physics involved is not directly tied with saturation.
Dr
Martin Spousta
(Charles University in Prague)
07/11/2013, 13:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
To Be Completed
Dr
Michael Lublinsky
(Ben-Gurion University of the Negev)
07/11/2013, 13:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
We address the relation between the long range two-particle correlations
observed at the LHC and the B-Reggeon. The latter is a four-point
generalization of the BFKL Pomeron also emerging as a new element of
the QCD Reggeon Field Theory.
Mr
Yasuki Tachibana
(The University of Tokyo)
07/11/2013, 14:10
Initial State and Proton-Nucleus Collision Phenomena
Oral
High energy partons propagating through the QGP medium are subject to deposit their energy and momentum into the medium. The dynamics of the QGP fluid would be affected by the energy-momentum deposition from these energetic partons. We study the collective flow of the QGP fluid induced by the jets using a (3+1)-dimensional QGP-fluid+Jet model. We simulate the propagation of jets together with...
Emilia Leogrande
(University of Utrecht)
07/11/2013, 14:10
Initial State and Proton-Nucleus Collision Phenomena
Oral
At LHC energies, several pairs of partons can collide in each pp, p-A or A-A collision. Multiple Parton Interactions (MPI) can affect many physical observables, such as the charged particle multiplicity and the average transverse momentum per event.
In order to include jets down to the lowest energies ("minijets"), a two-particle correlation analysis is performed with the ALICE Experiment....
Prof.
Fuqiang Wang
(Purdue University)
07/11/2013, 14:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
A long-range pseudo-rapidity correlation is unexpectedly observed in pp
and p+Pb collisions at the LHC after a uniform background subtraction.
It is called the "ridge," in analogy to the similar phenomenon in heavy-ion
collisions after subtraction of an elliptic-flow-modulated background.
The heavy-ion ridge has been attributed primarily to triangular anisotropy,
resulting from initial...
Marta Verweij
(Wayne State University)
07/11/2013, 14:30
Initial State and Proton-Nucleus Collision Phenomena
Oral
We present a measurement of jet correlations in p-Pb collisions at \sqrt{s}=5.02 TeV.
The aim of the measurement is to test whether cold nuclear matter effects and
shadowing are present in p-Pb collisions.
Jets are measured using the central detectors using the anti-kT jet algorithm.
In the analysis the underlying event is subtracted event-by-event.
Corrections for the remaining...
Mr
Ilkka Helenius
(University of Jyväskylä)
07/11/2013, 14:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
I will focus on the nuclear PDFs (nPDFs) and their applications in high energy A+A and p/d+A collisions. First, I will introduce our recently published spatially dependent nPDF sets, EPS09s and EKS98s, and discuss the centrality dependence of hard-process cross-sections within the collinear factorization framework. More specifically, I will compare our NLO pQCD calculations for the nuclear...
Tim Schuster
(Yale University)
07/11/2013, 14:50
Initial State and Proton-Nucleus Collision Phenomena
Oral
Two-particle correlation studies in high-multiplicity pp and p-Pb collisions at LHC energies have revealed unexpected structures. A symmetric double-ridge correlation pattern was found in p-Pb collisions at sqrt(s_NN)=5.02 TeV that extends to large differences in pseudorapidity. This observation can be attributed to collective behavior in the initial and final state of the collision using...
Prof.
Wolfgang Cassing
(Uni. Giessen)
07/11/2013, 15:40
Jet Quenching and Observables
Oral
We study the the non-equilibrium dynamics of heavy-ion
collisions from SIS to LHC energies within the Parton-Hadron-String
Dynamics (PHSD) transport approach, which incorporates explicit
partonic degrees of freedom in terms of strongly interacting
quasiparticles (quarks and gluons) in line with an equation of state
from lattice QCD as well as the dynamical hadronization and...
Dr
Francesco Scardina
(University of Catania (INFN-LNS))
07/11/2013, 16:00
Initial State and Proton-Nucleus Collision Phenomena
Oral
A current goal of relativistic heavy ion collisions experiments is the search for a Color Glass Condensate (CGC) as the limiting state of QCD matter at very high density. In viscous hydrodynamics simulations, a standard Glauber initial condition leads to estimate 4πη/s ∼ 1, while employing the Kharzeev-Levin-Nardi (KLN) modeling of the glasma leads to at least a factor of 2 larger η/s....
Mr
Risto Paatelainen
(University of Jyväskylä)
07/11/2013, 16:20
Initial State and Proton-Nucleus Collision Phenomena
Oral
We report the results from the recent studies [1,2], where we have brought the EKRT framework [3] to next-to-leading order (NLO) in pQCD, and shown the viability of the model in describing the produced initial QGP energy densities at the LHC and RHIC.
Our updated framework [1] combines a rigorous NLO pQCD computation of the minijet transverse energy production with the saturation of gluons...
Ramona Vogt
(LLNL and UC Davis, USA)
07/11/2013, 16:40
Initial State and Proton-Nucleus Collision Phenomena
Oral
Recently a compilation of predictions for charged hadron, identified light hadron, quarkonium, photon, jet and gauge boson production in p+Pb collisions at sqrt(s_NN) = 5 TeV was made available [1]. Here the predictions are compared to the data so far available.
[1] J. Albacete et al., Int. J. Mod. Phys. E22 (2013) 133007.
