Michael Weber
(University of Houston (US))
18/07/2013, 09:00
Ultrarelativistic Heavy Ions
Talk presentation
Recent measurements of two–particle correlations in high–multiplicity p–Pb collisions at √sNN = 5.02 TeV revealed a long–range structure (large separation in ∆η) at the near– (∆φ ≃ 0) and away–side (∆φ ≃ π) of the triggering particle [1, 2, 3]. At LHC energies, these ridge–like structures have already been observed in Pb–Pb collisions [4], but also in high–multiplicity pp collisions [5]. In...
Mauro Villa
(Universita e INFN (IT))
18/07/2013, 09:16
Ultrarelativistic Heavy Ions
Talk presentation
The ATLAS experiment has studied the centrality dependence of global event characteristics in proton-lead collisions at sqrt(s_NN)=5.02 TeV. A total integrated luminosity of 30nb-1 was collected during LHC proton-lead runs in the fall and winter of 2012-13. The centrality of proton-lead collisions was characterized using the total transverse energy measured in the ATLAS forward calorimeter on...
Monika Sharma
(Vanderbilt University (US))
18/07/2013, 09:32
Ultrarelativistic Heavy Ions
Talk presentation
Measurements of two- and four-particle angular correlations for charged particles emitted in pPb collisions are presented over a wide range in pseudorapidity and full azimuth at CMS. The results are compared to 2.76 TeV semi-peripheral PbPb collision data, collected during the 2011 PbPb run, covering a similar range of particle multiplicities. The observed correlations are characterized by the...
Klaus Werner
(Univ Nantes)
18/07/2013, 09:48
Ultrarelativistic Heavy Ions
Talk presentation
There is little doubt that flow has been observed in heavy ion collisions at the LHC and RHIC, mainly based on results on azimuthal anisotropies, but also on particle spectra of identified particles,
perfectly compatible with hydrodynamic expansions.
Surprisingly, in pPb collisions one observes a quite similar behavior. So do we observe hydrodynamic dynamics as well in pPb?
We will try to...
Antoni Szczurek
(Institute of Nuclear Physics)
18/07/2013, 10:08
Ultrarelativistic Heavy Ions
Talk presentation
We estimate the electromagnetic effect of the spectator charge on
azimuthal anisotropies observed in heavy ion collisions. For peripheral
Pb+Pb reactions at the top energy of the CERN Super Proton Synchrotron,
$\sqrt{s_{NN}}=17.3$ GeV, we predict this effect to bring very large
distortions to the observed directed flow, $v_1$, of positive and
negative pions emitted close to beam...
Peter Christiansen
(Lund University (SE))
18/07/2013, 11:00
Ultrarelativistic Heavy Ions
Talk presentation
\begin{center}
{\large \bf Identified charged pion, kaon, and proton production in pp and Pb-Pb collisions at LHC energies measured with ALICE}
{\bf P.~Christiansen}$^{\rm a}$ for the ALICE Collaboration.
\vspace{12pt}
$^{\rm a}$Department of Physics, Particle Physics, Lund
University,\\
SE-221 00 Lund, Sweden,\\
\textit{peter.christiansen@hep.lu.se}
\vspace{12pt}...
Tuomas Lappi
(University of Jyvaskyla)
18/07/2013, 11:16
Ultrarelativistic Heavy Ions
This talk reviews theory predictions for charged hadron production in pA collisions at LHC energies. In particular the emphasis is on the difference between models incorporating initial and final state effects on the production of (semi)hard particles.
Fanfan Jing
(Tsinghua University (CN))
18/07/2013, 11:36
Ultrarelativistic Heavy Ions
Talk presentation
With a unique forward acceptance, and excellent vertexing and particle identification capability, LHCb is well-placed to make important contributions to heavy ion physics through measurements performed using data taken during pA and Ap collisions. The first studies of these data will be presented. These include measurements of particle multiplicity and studies of strange and charmed...
Krisztian Krajczar
(CERN)
18/07/2013, 11:56
Ultrarelativistic Heavy Ions
Talk presentation
Spectra of inclusive and identified charged hadrons measured in p-Pb collisions at the LHC at sqrt(sNN) = 5 TeV are presented. Charged pions, kaons, and protons in the transverse-momentum range pT = 0.1-1.7 GeV/c and for central rapidities are identified via their energy loss in the CMS silicon tracker. Inclusive charged hadron spectra are studied as a function of pseudorapidity. The fully...
Roberto Preghenella
(Universita e INFN (IT))
18/07/2013, 12:12
Ultrarelativistic Heavy Ions
Talk presentation
Hadron production has been measured at mid-rapidity by the ALICE experiment at the LHC in proton-lead (p--Pb) collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. The transverse momentum ($p_{\rm T}$) distribution of primary charged particles and of identified light-flavoured hadrons ($\pi^{\pm}$, K$^{\pm}$, K$^{0}_{\rm S}$, p, $\bar{\rm p}$, $\Lambda$, $\bar{\Lambda}$) are presented in this report....
Martin Makariev
(Bulgarian Academy of Sciences (BG))
18/07/2013, 12:28
Ultrarelativistic Heavy Ions
Talk presentation
In the framework of a general study of hadron production in elementary and nuclear interactions at the CERN SPS the NA49 experiment has produced new and complete sets of inclusive meson and baryon cross sections in p+p and p+C interactions [1-8]. This work is aimed at providing precision data over most of the available phase space with a special emphasis on completeness, internal consistency...
Andrea Quadri
(INFN, Sez. di Milano)
18/07/2013, 12:44
Ultrarelativistic Heavy Ions
Talk presentation
We show that a very powerful Slavnov-Taylor (ST) identity exists
for the Effective Field Theory (EFT) of the Color Glass Condensate (CGC), allowing to control by purely algebraic means the full dependence on the background fields of the ultra-fast gluon modes, as well as the correlators of the quantum fluctuations of the classical gluon source.
We use this formalism to study the change of...
Alessandro Grelli
(University of Utrecht (NL))
18/07/2013, 14:30
Ultrarelativistic Heavy Ions
Talk presentation
Hadrons containing heavy flavours are unique probes of the properties of the hot and dense QCD medium produced in heavy ion collisions. Due to their large masses, heavy quarks are produced at the initial stage of the collision, almost exclusively via hard partonic scattering processes. Therefore, they are expected to experience the full collision history propagating through and interacting...
Mr
David Tlusty
(NPI ASCR)
18/07/2013, 14:46
Ultrarelativistic Heavy Ions
Talk presentation
In relativistic heavy ion collisions at RHIC, heavy quarks are expected to be created from initial hard scatterings. Their large masses are not easily affected by the strong interaction with QCD medium, thus they carry clean information from the system at early stage. The interaction between heavy quarks and the medium is sensitive to the medium dynamics, therefore heavy quarks are suggested...
Olga Hajkova
(C)
18/07/2013, 15:02
Ultrarelativistic Heavy Ions
Talk presentation
Hot and dense matter in which quarks and gluons are deconfined is created in heavy-ion collisons at RHIC. The properties of this strongly interacting matter, Quark-Gluon Plasma, could be studied using heavy quarks, namely charm and bottom. Due to their large masses, they are produced during the initial phase of heavy ion collisions via gluon fusion. Non-photonic electrons (NPE) are mainly...
Hendrik van Hees
(Goethe University Frankfurt)
18/07/2013, 15:18
Ultrarelativistic Heavy Ions
Talk presentation
The heavy charm and bottom quarks and the associated open heavy-flavor mesons (D and B) are a valuable probe for the interactions in the hot and dense medium created in heavy-ion collisions. They are produced in the primordial hard collisions of partons within the nuclei and then traverse the hot and dense partonic (QGP) and hadronic (hadron gas) medium, which shows collective behavior,...
Chiara Bianchin
(University of Utrecht (NL))
18/07/2013, 15:38
Ultrarelativistic Heavy Ions
Talk presentation
The ALICE experiment at the LHC studies Pb-Pb, pp, and p-Pb collisions with the aim of investigating the properties of the high-density state of strongly-interacting matter, expected to be produced in Pb-Pb collisions.
Heavy quarks are sensitive probes to test the medium transport properties and its degree of thermalization since they are formed at shorter time scale with respect to the...
Alexander Philipp Kalweit
(CERN)
18/07/2013, 16:30
Ultrarelativistic Heavy Ions
Talk presentation
The unprecedented high collision energies at the Large Hadron Collider give rise to a significant production of light anti- and hyper-nuclei in proton-proton and, even more, in Pb-Pb collisions. With its excellent particle identification capabilities based on the specific energy loss (dE/dx) in the Time Projection Chamber and time-of-flight measurements, the ALICE experiment is very well...
Maciej Rybczynski
(Jan Kochanowski University (PL))
18/07/2013, 16:46
Ultrarelativistic Heavy Ions
Talk presentation
The exploration of the QCD phase diagram and particularly the search
for a phase transition from hadronic to partonic degrees of freedom and possibly a critical endpoint, is one of the most challenging tasks in present heavy-ion physics.
As observed by the NA49 experiment, several hadronic observables in central Pb+Pb collisions at the CERN SPS show qualitative changes in their energy...
Michal Sumbera
(Acad. of Sciences of the Czech Rep. (CZ))
18/07/2013, 17:02
Ultrarelativistic Heavy Ions
Talk presentation
Results from the Beam Energy Scan (BES) program conducted recently by STAR
experiment at RHIC are presented. The data from Phase-I of the BES program
collected in Au+Au collisions at center-of-mass energies (\sqrt{s_{NN}})
of 7.7, 11.5, 19.6, 27, and 39 GeV cover a wide range of baryon chemical
potential \mu_B (100-400 MeV) in the QCD phase diagram. Several STAR
results from the BES...
Prof.
Hugo Reinhardt
(Tuebingen University)
18/07/2013, 17:18
Ultrarelativistic Heavy Ions
Talk presentation
The effective potential of the order parameter for confinement is calculated for SU(N) Yang-Mills theory in the Hamiltonian approach. Compactifying one spatial dimension and using a background gauge fixing, this potential is obtained within a variational approach by minimizing the energy density for given background field. Thereby, the inverse length of the compactified dimension represents...
Dr
Enrico Fragiacomo
(INFN Trieste (IT))
18/07/2013, 17:38
Ultrarelativistic Heavy Ions
Talk presentation
Hadronic resonance production in pp and Pb-Pb collisions at LHC with the ALICE experiment
Enrico Fragiacomo
INFN Trieste
on behalf of the ALICE Collaboration
Abstract
Resonances, with their lifetime comparable to the lifetime of the partonic plasma phase, are a valuable tool to study the dynamics of the high energy density medium formed in heavy-ion collisions. Resonance...
Dr
Rikard Sandstrom
(Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)
18/07/2013, 17:54
Ultrarelativistic Heavy Ions
Talk presentation
During the first three years of operation the ATLAS experiment has collected an integrated luminosity of 0.15 nb-1 for sqrt(s_NN)=2.76 TeV lead-lead collisions,
30 nb-1 for 5.02 TeV proton-lead collisions, and 5 pb-1 for sqrt(s)=2.76 TeV proton-proton collisions. The proton-lead and the high-statistics 2.76 TeV proton-proton data recorded during the highly successful 2013 LHC heavy ion run...
Massimiliano Marchisone
(Universita e INFN (IT))
19/07/2013, 09:00
Ultrarelativistic Heavy Ions
Talk presentation
Ultra-relativistic heavy ion collisions produce strongly interacting matter at high temperature and energy density.
Under such extreme conditions a deconfined partonic phase called Quark-Gluon Plasma (QGP) is formed.
The measurement of quarkonia (charmonia and bottomonia) is expected to provide essential information on the QGP properties.
In pp collisions high precision data serve as...
Francois Arleo
(LAPTH, Annecy-le-Vieux)
19/07/2013, 09:16
Ultrarelativistic Heavy Ions
Talk presentation
The effects of parton energy loss in cold nuclear matter on heavy-quarkonium suppression in p-A collisions are studied. It is shown from first principles that at large quarkonium energy E and small production angle in the nucleus rest frame, the medium-induced energy loss scales as E. Using this result, a phenomenological model depending on a single free parameter is able to reproduce J/psi...
Joakim Nystrand
(University of Bergen (NO))
19/07/2013, 09:36
Ultrarelativistic Heavy Ions
Talk presentation
The strong electromagnetic fields surrounding the Pb-ions accelerated
at the CERN Large Hadron Collider (LHC) allow two-photon and
photonuclear interactions to be studied in a new kinematic regime.
These interactions can be studied in ultra-peripheral collisions,
where the impact parameters are larger than the sum of the nuclear
radii and hadronic interactions are suppressed.
During...
Max Klein
(University of Liverpool (GB))
19/07/2013, 09:52
Ultrarelativistic Heavy Ions
Talk presentation
The Large Hadron Electron Collider (LHeC) is a proposed facility which will exploit the LHC heavy ion beam for electron-nucleus scattering, using a new 60 GeV electron accelerator. The kinematic coverage extends beyond previous deep inelastic lepton-ion experiments by nearly four orders of magnitude at low Bjorken-x and towards higher Q^2. This contribution summarises the content of the...
Ermias Atomssa
(Stony Brook University)
19/07/2013, 10:12
Ultrarelativistic Heavy Ions
Talk presentation
As the study of the hot and dense medium created in ultra-relativistic heavy ion collisions advances from an exploratory phase to a more quantitative and detailed approach, the PHENIX experiment is exploiting the unique opportunities offered by the versatility of the Relativistic Heavy Ion Collider. Measurements from d+Au collisions are providing crucial new information about the cold nuclear...
Liliana Apolinario
(Universidade de Santiago de Compostela (ES))
19/07/2013, 11:00
Ultrarelativistic Heavy Ions
Talk presentation
Motivated by the new experimental capabilities of the LHC and the new results from heavy-ion experiments, several extensions of the standard calculations of energy loss have been made recently. In this presentation, I will provide a short overview of recent developments in jet quenching theory. First, I will discuss some improvements computed by different groups to implement energy-momentum...
Rudiger Haake
(Westfaelische Wilhelms-Universitaet Muenster (DE))
19/07/2013, 11:20
Ultrarelativistic Heavy Ions
Talk presentation
Rüdiger Haake, Westfälische Wilhelms-Universität Münster, Germany
on behalf of the ALICE collaboration
Highly energetic jets are sensitive probes for the kinematics and the topology of high energy collisions. They are produced in an early stage of the collision from hard scattered partons that hadronize and eventually form jets as a spray of charged and neutral particles.
The measurement...
Jan Rusnak
(N)
19/07/2013, 11:36
Ultrarelativistic Heavy Ions
Talk presentation
Jets are collimated sprays of particles arising from the fragmentation of hard-scattered partons in high-energy collisions.
In collisions of heavy nuclei, jets serve as probes of the hot and dense nuclear matter created, and the study of the modification of their structure due to interaction with the surrounding medium (known as "jet quenching") is an important tool for understanding the...
Peter Levai
(Hungarian Academy of Sciences (HU))
19/07/2013, 11:52
Ultrarelativistic Heavy Ions
Talk presentation
Hadron production in relativistic heavy ion collisions usually consists of two main channels in the intermediate-pT region at RHIC and LHC energies: parton coalescence/recombination and jet fragmentation. We have explored a new channel, namely hadron production from strong time dependent coherent field produced in heavy ion collisions. One can investigate direct hadron production from strong...
Matthew Nguyen
(Ecole Polytechnique (FR))
19/07/2013, 12:12
Ultrarelativistic Heavy Ions
Talk presentation
Jets are an important tool to probe the medium produced in ultra-relativistic heavy ion collisions. In PbPb collisions a significant energy loss (jet quenching) of the partons traversing the hot and dense medium has been observed and quantified through a variety of measurements: dijet momentum imbalance, photon-jet correlations, measurements of the fragmentation pattern and the jet shapes,...
Ewelina Maria Lobodzinska
(Deutsches Elektronen-Synchrotron (DE))
19/07/2013, 12:28
Ultrarelativistic Heavy Ions
Talk presentation
ATLAS presents the first result of the measurement of the jets and electroweak bosons in proton-lead collisions at sqrt(s_NN)=5.02 TeV. The data was obtained during the LHC 2013 proton-lead with integrated luminosity of approximately 30nb-1. Forward jet production in proton-lead collisions is expected to be sensitive to saturation of parton distribution in the lead nucleus. ATLAS measurements...
Pelin Kurt Garberson
(University of Illinois at Chicago (US))
19/07/2013, 12:44
An overview of the most recent results on jet quenching physics obtained using PbPb collision data collected with the CMS experiment at 2.76 TeV will be presented. These measurements make use of many different observables, including momentum imbalance of dijet and photon-jet events, nuclear modification factor RAA, as well as jet fragmentation functions, jet shapes, and flavor dependence of...
