# Second conference on heavy ion collisions in the LHC era and beyond

Asia/Ho_Chi_Minh
Quy Nhon, Vietnam

#### Quy Nhon, Vietnam

International Center of Interdisciplinary Science Education (ICISE)
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Description

The Second Conference on Heavy Ion Collisions in the LHC era and beyond, taking place in Quy Nhon on 26-31 July 2015, will focus on the physics of proton-nucleus and nucleus-nucleus collisions at RHIC and LHC, and will explore future capabilities. Results accumulated by the RHIC/LHC experiments and recent theoretical developments will be presented on the following topics:

• A: Global and Collective Dynamics
• B: Jet quenching
• C: Heavy Flavor and Quarkonia Production
• D: Electroweak Probes
• E: QCD at High Temperature and Density & Phase Diagram
• F: Pre-equilibrium and Initial State Physics

We will aim to achieve a balance between review talks given by recognised specialists, and shorter contributions, special emphasis being placed on active participation by younger researchers and post-docs. Parallel sessions are foreseen, and are being organised as the need arises. The inaugural opening talk will be given by Prof. Jerome I. Friedman, Nobel Prize of Physics in 1990.

This conference is part of a series of international meetings held regularly in Vietnam, created by Jean Tran Thân Van in 1993. Their purpose is to stimulate the development of advanced research in Vietnam and more generally in South East Asia, and to establish collaborative research networks with Western scientific communities.

The conference will take place in Quy Nhon,Vietnam, from Sunday, July 26th to Friday, July 31st, 2015 in the new International Center of Interdisciplinary Science Education ICISE (see leaflet and video). The Center has been inaugurated on August 12, 2013 during the Inaugural Conference Windows on the Universe. The center is located in an exceptional location near the sea, close to a small town situated on the east coast of Vietnam, one hour north by air from Ho-Chi-Minh City (Saigon).

Participants
• Avdhesh Kumar
• Byungsik Hong
• Christian Schmidt-Sonntag
• Christoph Herold
• Chun Shen
• Claudia Ratti
• David Zaslavsky
• Fabio Dominguez
• Francesca Bellini
• Francois Arleo
• Fuming Liu
• Hang Pham
• Hong-Fei Zhang
• Horst Stoecker
• Huichao Song
• Huu Ha Nguyen
• Jean-Philippe Lansberg
• Jerome I. Friedman
• Kazuhiro Watanabe
• Koichi Murase
• Krzysztof Kutak
• Maitreyee Mukherjee
• Manoel R. Moldes
• Marco Panero
• Marco Ruggieri
• Min Jung Kweon
• Munshi Golam Mustafa
• Qipeng Hu
• Qun Wang
• Rene Bellwied
• Sangwook Ryu
• Santosh Das
• Senosi Kgotlaesele Johnson
• Somorendro Singh Shougaijam
• Stefan Floerchinger
• Thi Hien Doan
• Vinod Chandra
• Vitalii Ozvenchuk
• Wei Li
• Wilke van der Schee
• Xu-Guang Huang
• Yen-Jie Lee
• Yunpeng Liu
• Sunday, 26 July
• 19:00 20:00
Welcome cocktail 1h
• Monday, 27 July
• 09:00 12:30
Opening Session
• 09:00
Conference opening 30m
• 09:30
Coffee break and late registration 30m
• 10:00
The discovery of quarks 45m
Speaker: Prof. Jerome I. Friedman (MIT)
• 10:45
Break 15m
• 11:00
Pure Gluon Plasma and the first order phase transition to the glueball fluid at RHIC and LHC 45m
Speaker: Prof. Horst Stoecker (GSI)
• 12:30 14:00
Lunch 1h 30m
• 14:00 18:00
Global and Collective Dynamics
• 14:00
Hydrodynamics with baryon diffusion — recent developments for the RHIC Beam Energy Scan program 30m
In this talk, I will summarize recent theoretical efforts to understand the flow measurements in the BNL Beam Energy Scan (BES) program. The measured bulk flow observables at these collision energies and their collision energy dependence has not been understood on a quantitative level yet. This motivates us to improve our current theoretical modeling for the heavy-ion collisions at these low collision energies. I will then discuss our recent theoretical development of including baryon diffusion to model the relativistic heavy-ion collisions from 7.7 A GeV to 200 A GeV for the RHIC BES program. The consequences from the existences of conserved net baryon current, its diffusion, and non-boost invariant initial conditions to the final flow observables will be discussed.
Speaker: Dr Chun Shen (McGill University)
• 14:30
Properties of the QGP and its hadronization based on correlation and fluctuation measurements at RHIC and the LHC 30m
I will review the latest results from RHIC and LHC on correlation and fluctuation measurements. I will relate the deduced transport properties of the QGP to possible mechanisms of hadronization in the QCD crossover region, which manifest themselves in higher order fluctuations. Comparisons of lattice QCD and statistical equilibrium's models might allow us to shed light on the transition process from deconfined partons to hadrons. The possibility of producing exotic states during this transition will be discussed as well.
Speaker: Rene Bellwied (University of Houston (US))
• 15:00
Collective dynamics of small systems 30m
I will review recent experimental progress in studying collective phenomena in small colliding systems with high-multiplicity final state at RHIC and the LHC.
Speaker: Wei Li (Rice University (US))
• 15:30
Coffee break 30m
• 16:00
Effects of event-by-event hydrodynamic fluctuations in an integrated dynamical model 30m
The *hydrodynamic fluctuations* are thermal fluctuations arising in the event-by-event hydrodynamic evolution of the system, and they have effects on heavy-ion observables such as the higher harmonics $v_n$. To quantitatively determine the matter properties such as the shear viscosity and the relaxation times, it is needed to take into account the hydrodynamic fluctuations as well as the initial-state fluctuations. The hydrodynamic fluctuations appear in the constitutive equation, and their power spectrum is determined by the fluctuation-dissipation relation. We implement the hydrodynamic fluctuations in our dynamical model consisting of the initialization models such as Monte-Carlo KLN model, causal dissipative hydrodynamics, and the subsequent hadronic cascades. By analyzing the hadron distributions obtained by massive event-by-event calculations with both of the hydrodynamic fluctuations and the initial-state fluctuations, we investigate the effects of the hydrodynamic fluctuations on the observables such as the higher harmonics.
Speaker: Koichi Murase (The University of Tokyo)
• 16:30
Net-baryon skewness and kurtosis from nonequilibrium fluid dynamics 30m
Recent data from the beam-energy scan at RHIC has shown interesting behavior in the region of large baryon densities, where a significant increase in the net-proton kurtosis has been reported. We model the dynamical QCD phase transition in heavy-ion collisions using chiral fluid dynamics. This model is able to describe relevant nonequilibrium effects that other hydrodynamic models lack. We calculate particle multiplicities from a freeze-out over an energy hypersurface to determine the skewness and kurtosis as signs of non-Gaussian event-by-event fluctuations. Our results show good qualitative agreement with the experimental data. Special emphasis is put on the role of the equation of state, which is demonstrated to have crucial influence on the kurtosis for lower beam energies.
Speaker: Christoph Herold (Suranaree University of Technology)
• Tuesday, 28 July
• 09:00 12:30
QCD at High Temperature and Density & Phase Diagram
• 09:15
Hot QCD and QCD-like theories on the lattice 45m
In the first part of this contribution, I will give a non-technical introduction to lattice calculations, which are the standard tool to derive ab initio theoretical predictions for QCD at finite temperature. Then I will present a selection of recent, high-precision numerical lattice QCD results relevant for heavy-ion collisions. Finally, I will also discuss some analytical and conceptual insights into the physics of the quark-gluon plasma, that are obtained by generalizing lattice calculations to theories based on different gauge groups and/or in different spacetime dimensions, and combining them with other theoretical approaches (including weak- or strong-coupling techniques, effective field theories or phenomenological models).
Speaker: Marco Panero (University of Turin and INFN, Turin)
• 10:00
Chiral fermions in quantum kinetic approach 30m
Kinetic theory is an important tool to describe these phenomena in phase space of chiral fermions. It has been shown that the CME, CVE and Covariant Chiral Kinetic Equation (CCKE) can be derived in quantum kinetic theory from the Wigner function in 4-dimensions (4D) in external electromagnetic fields. The magnetic moment and spin-vorticity coupling of chiral fermions are shown to emerge in 4-dimensional Wigner functions. In linear response theory with space-time varying electromagnetic fields, the parity-odd part of the electric conductivity can also be derived which reproduces results of the one-loop and the hard-thermal or hard-dense loop. All these properties show that the 4-dimensional Wigner functions capture comprehensive aspects of physics for chiral fermions in electromagnetic fields.
Speaker: Prof. Qun Wang (University of Science and Technology of China)
• 10:30
Coffee break 30m
• 11:00
Probing hot QCD matter and the fireball evolution with light-flavour hadrons in ALICE 30m
Probing hot QCD matter and the fireball evolution with light-flavour hadrons in ALICE
Speaker: Francesca Bellini (Universita e INFN, Bologna (IT))
• 11:30
Systematics of higher order net-baryon number fluctuations at small values of the baryon chemical potential 30m
We analyze cumulant ratios of net-baryon number fluctuations calculated in (2+1)-flavor QCD in next-to-leading order (NLO) Taylor expansions in terms of temperature and the conserved charge chemical potentials for baryon number, strangeness and electric charge. We approximate the conditions met in heavy ion collision by enforcing strangeness neutrality and a constant baryon number to electric charge ratio. We show that fourth-order results are sufficient to model dense matter created in heavy ion collisions with center-of-mass energies down to $s^{1/2}_{NN} \sim 20 GeV$ and use Sixth-order results to estimate truncation errors. We discuss to what extent the pattern seen in the RHIC beam energy scan of up to 4th order cumulants of electric charge and proton (baryon) number fluctuations can be understood in terms of QCD equilibrium thermodynamics. The results are based on lattice calculations performed with the Highly Improved Staggered Quark action (HISQ) in the temperature range 140 MeV < T < 330 MeV, with lattice sizes 24^3 \times 6, 32^3 \times 8 and 48^3 \times 12. The strange quark mass is tuned to its physical value and we use a strange to light quark mass ratio m_s/m_l = 20, which in the continuum limit corresponds to a pion mass of about 160 MeV.
Speaker: Christian Schmidt (University of Bielefeld)
• 12:30 14:00
Lunch 1h 30m
• 14:00 17:30
Electroweak Probes
• 14:00
Recent developments in the theory of electromagnetic probes in relativistic heavy-ion collisions 30m
Electromagnetic probes are considered as clean messengers from the hot dense medium created in the Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC). In this talk, I will review the theoretical developments in the study of electromagnetic radiation in relativistic heavy-ion collisions. The recent progress in the rates for photon and lepton pair production is discussed. Together with the improvements in the hydrodynamic descriptions of the bulk medium, I will emphasise the combined efforts to resolve the "direct photon flow puzzle" in the RHIC and the LHC experiments. Further prediction of the direct photon production in high multiplicity proton-nucleus collisions at the LHC energy can serve as a signature of the quark gluon plasma formation in these small systems.
Speaker: Dr Chun Shen (McGill University)
• 14:30
Electroweak Bosons in Heavy Ion Collisions with the ATLAS Detector 30m
Electroweak bosons processes (W, Z and photon) provide experimental controls over initial geometric and nuclear PDFs (nPDFs). The ATLAS has measured the production of all three bosons in Pb+Pb at 2.76 TeV and the production of Z bosons in p+Pb collisions at 5.02 TeV. Z bosons are measured via both di-electron and di-muon decay channel. W bosons are measured with isolated single leptons and missing transverse energy constructed from tracks. Photons are measured using ATLAS electromagnetic calorimeter and calorimeter-based isolation observables. The yields of all three bosons in Pb+Pb collisions are found to obey binary collision scaling. But Run 1 Pb+Pb data is not yet sensitive enough to discern specific features of nPDF effects. The Z yield in p+Pb collisions provide another excellent opportunity to test nPDF effects. In addition, the centrality dependence of Z boson production in p+Pb is measured and analyzed within standard Glauber model and the Glauber-Gribov model with event-by-event fluctuations. The effects of hard scattering biases on the centrality categorization in p+Pb are addressed.
Speaker: Qipeng Hu (University of Science and Technology of China (CN))
• 15:00
Electroweak boson results from CMS 30m
Electroweak production is an important benchmark in heavy-ion collisions at the LHC. Electroweak bosons (W and Z) do not participate in strong interaction and their leptonic decays play as an idea tag to probe properties of jets that interact with the medium strongly. They, moreover, constrain nuclear parton distribution functions (nPDFs) in unexplored region of Q^2 - x phase space. They can also provide insights into the parton distribution function of neutrons. Measurement of W and Z bosons in pPb collision at 5.02 TeV will be presented in both muon and electron channel decays. The results are compared to theory prediction with and without nuclear modification. In addition, final results of W and Z production in PbPb collisions at 2.76 TeV compared to pp at the same energy collisions will also be mentioned.
Speaker: Thi Hien Doan (National Central University (TW))
• 15:30
Coffee break 30m
• 16:00
Measurements of W boson production in p-Pb collisions at the LHC with ALICE 30m
ALICE (A Large Ion Collider Experiment) is designed and optimized to study ultra-relativistic heavy-ion collisions, in which a hot and dense, strongly-interacting medium is created. W bosons are produced in hard scattering processes and interact weakly with the medium formed in heavy-ion collisions. Thus, these electroweak bosons are suitable references for processes which are heavily affected by the medium. In proton-nucleus collisions the production of W bosons is suitable to study the modification of parton distribution functions in the nucleus and to test the validity of binary collision scaling. The latter is studied by measuring the yield of W bosons in different intervals of event activity. The production of W bosons is studied in p--Pb collisions at a center-of-mass energy of $\sqrt {s_{\rm NN}}$ = 5.02 TeV with the ALICE muon spectrometer at forward ($2.03 < \mathit{y}^{\mu}_{\textrm{cms}} < 3.53$) and backward rapidity ($-4.46< \mathit{y}^{\mu}_{\textrm{cms}} <-2.96$). The W-boson signal is extracted from the inclusive single muon differential $p_{\rm T}$ spectrum. Recent results are discussed, and the measured cross sections are compared to perturbative Quantum Chromodynamics calculations at next-to-leading order.
Speaker: Kgotlaesele Senosi (University of Cape Town (ZA))
• 16:30
Direct photon v2 puzzle in heavy ion collisions 30m
We reproduced the observed large v2, v3 of direct photons and predicted a large v2, v3 of thermal dileptons based on EPOS 3, a hadron data constrained (3+1)D viscous hydro model and normal emission rates of photons and dileptons from QGP phase and hadronic gas phase. Direct photon v2 is in fact a puzzle for our field for quite long time. Why can EPOS3 reproduce the challenging experimental data ? We have to understand it. Model comparison will be helpful. In this conference, I will share everybody what we have found.
Speaker: Fu-Ming Liu (Central China Normal University)
• Wednesday, 29 July
• 09:15 12:30
Heavy Flavor and Quarkonia Production
• 09:15
Review of quarkonium production mechanism in pp collisions from low to high p_t 45m
Quarkonium suppression is one of the key evidences for the QGP. To quantitatively study the suppression, one needs to understand the underlying quarkonium production mechanism. In this talk, I will briefly review the recent progresses on the quarkonium production and polarization, especially at hadron colliders, from low to high pt, including the nonrelativistic QCD (NRQCD) effective theory, the current status of the J/ψ polarization puzzle, the color-glass-condenstate (CGC) plus NRQCD model in the contribution of small pt predictions, and miscellaneous.
Speaker: Hong-Fei Zhang
• 10:00
Open heavy flavor results from RHIC and the LHC 30m
Hadrons carrying open heavy flavor have been a useful tool in studying the strongly interacting matter produced in ultra-relativistic heavy-ion collisions. Since heavy flavor quarks are produced early in the collision, they experience the full evolution of the medium and are thus a good probe of medium effects. Studying open heavy flavor in p(d)+A and A+A collisions can allow for the quantification of cold nuclear matter effects and energy loss in the produced hot medium. Early measurements from the Relativistic Heavy Ion Collider (RHIC) showed interesting results that prompted further studies over a course of different collision species and kinematic regions. The addition of data from the Large Hadron Collider (LHC) at CERN further extends these measurements to higher collision energies. Open heavy flavor results from both RHIC and the LHC will be presented and discussed as they relate to our further understanding of how heavy quarks are affected by the medium produced in ultra-relativistic heavy-ion collisions.
• 10:30
Coffee break 30m
• 11:00
Quarkonium production in heavy-ion collisions at RHIC and LHC 30m
Since late 80's when the relativistic heavy-ion experiments started at AGS and SPS, the quarkonium production has been regarded as one of the golden probes for the deconfined phase transition of the hadronic matter to the quark-gluon plasma (QGP). The heavy quarkonia can be generated in gluon-gluon scatterings at early stage of the collision as the large momentum transfer is required. Later the binding potential between a quark and its antiquark in quarkonium is screened by surrounding light quarks and antiquarks. Thus, the various quarkonium states are expected to be melt at different temperatures depending on their binding energies, which allows us to characterize the QCD phase transition. At collider energies, the suppression of the J/psi yield in Au + Au and other lighter systems were obeserved by the PHENIX and STAR Collaborations at the Relativistic Heavy Ion Collider (RHIC) at BNL more than a decade ago. More recently, the suppression of the yields for the J/psi and Upsilon families in Pb + Pb collisions was also observed by the ALICE and CMS Collaborations at the Large Hadron Collider (LHC). Although the suppression of the various quarkonium yields in heavy-ion collisions when compared to those in p + p is a general trend, the detailed suppression pattern is different for each particle species, depending on the rapidity, momentum, and collision centrality. In this presentation, we are going to review the quarkonium data at RHIC and LHC, and will discuss possible implications related to the propagation of quarkonia in the deconfined hot, dense matter.
Speaker: Byungsik Hong (Korea University (KR))
• 11:30
Prospects on heavy-flavour measurements from Run 2 and the detector upgrades at the LHC and RHIC 30m
During Run 2, the LHC will further explore the properties of quark-gluon plasma via heavy-flavour measurement thanks to large statistics data samples allowing more detailed measurement. The prospects on heavy-flavour measurements from Run 2 and the detector upgrades at the LHC for Run 3 and Run 4 will be overviewed. Furthermore, the most recent result of heavy-flavour measurement and detector upgrade for heavy-flavour observables at the RHIC will be discussed.
Speaker: Min Jung Kweon (Inha University (KR))
• 12:30 14:00
Lunch 1d 1h 30m
• 14:00 18:00
Social excursion
• Thursday, 30 July
• 09:00 12:30
Jet quenching and energy loss
• 09:00
E-by-E description of jet energy loss with MARTINI and UrQMD 30m
We present a hybrid model containing viscous hydrodynamics (MUSIC), jets (MARTINI) and transport model (UrQMD) for heavy ion collision. While our previous work to couple viscous hydrodynamics and hadronic cascade is aimed to describe the low-$p_T$ regime, the improved event generator with MARTINI jets is capable of simulating the intermediate and high-$p_T$ regimes as well. We describe the MUSIC+MARTINI+UrQMD hybrid model with the IP-Glasma initial conditions and show that it can provide reasonable descriptions of the nuclear modification factor $R_{AA}$ and anisotropic flow coefficients $v_n$ at the intermediate and high-$p_T$ regimes. The effects of hadronic rescattering in the jet energy loss also will be shown.
Speaker: Sangwook Ryu (McGill University)
• 09:30
Jet quenching results from CMS 30m
This talk reviews recent experimental results on jet production and properties in heavy-ion collisions from the CMS Collaboration, including jet spectra, jet fragmentation pattern, angular distribution of the quenched energy, photon-jet and dijet asymmetry. The presented results utilize the high statistics pPb data at center-of-mass energy of 5.02 TeV and PbPb data at 2.76 TeV collected in 2011-13 at the LHC.
Speaker: Yen-Jie Lee (Massachusetts Inst. of Technology (US))
• 10:00
Interplay between hydrodynamics and jets 30m
I discuss different dissipative processes in the fluid dynamics of heavy ion collisions and in particular the influence of jets which transfer energy and momentum to the fluid. Quantitatively, the energy and momentum lost by jets is modeled by the jet quenching Monte Carlo Jewel with a realistic fluid dynamic model for the background. On the level of event averaged source terms the effects are small and are caused mainly by the momentum transfer. For the nuclear modification factor of jets and the di-jet asymmetry, Jewel leads to a reasonable agreement with experimental data.
Speaker: Stefan Floerchinger (CERN)
• 10:30
Coffee break 30m
• 11:00
Mass and color coherence in antennas 30m
Interference effects in jet parton showers are of great importance to the jet quenching phenomenon observed in high-energy nuclear collisions. We show how to study this intra-jet color coherence effects inside a QCD medium and the role that the mass of the heavy quarks has in it and its relation to the energy loss pattern.
Speaker: Manoel R. Moldes
• 11:30
Jets in holography 30m
Jets in holography
Speaker: Wilke van der Schee (MIT)
• 12:30 14:00
Lunch 1h 30m
• 14:00 14:30
Jet quenching and energy loss
• 14:00
Coherent energy loss and the production of hadrons in nuclear collisions 30m
Over the last few years we have shown that coherent energy loss in cold nuclear matter could play a decisive role in the production of hadrons in nuclear collisions. In the first part of the talk I will review our current understanding of coherent energy loss and its phenomenological consequences on quarkonium suppression in p–A and A–A collisions, from fixed target to collider energies. The second part of the talk will be devoted to the quenching of light hadron spectra in p–A collisions due to coherent energy loss effects.
Speaker: Francois Arleo (LAPTH, Annecy-le-Vieux)
• 14:30 15:00
Heavy Flavor and Quarkonia Production
• 14:30
D-meson observables in p-Pb collisions at LHC with MC@sHQ+EPOS3 model 30m
The first experimental results from pPb collisions at 5 TeV on the particle yields and azimuthal anisotropies as function of transverse momentum show a very similar behavior in comparison to the observations in heavy-ion collisions, where the quark-gluon plasma (QGP) can be produced. Such pPb results have indeed been explained in the framework of models including a QGP phase such as EPOS3. Heavy-flavor particles have been suggested as a good probe to study the properties of the QGP. Heavy quarks (HQ) are produced in the initial hard nucleon-nucleon scatterings and their thermal equilibration time is larger than the QGP lifetime. In this contribution we study the D-meson observables in pPb collisions at 5 TeV as it offers a complementary perspective with respect to light hadrons production. We calculate the nuclear modification factor of D mesons in pPb collisions using the MC@sHQ+EPOS3 model. It couples a Monte Carlo propagation of HQ to the 3+1 dimensional fluid dynamical evolution of the QGP from EPOS3 initial conditions, which combine pQCD calculations of the hard scattering with the Gribov-Regge theory. HQ that in EPOS3 can be produced during the spacelike cascade, the born process and the partonic shower, interact with plasma partons by either elastic or radiative collisions. The HQ form hadrons via coalescence or fragmentation on the hypersurface of constant temperature T=155 MeV. The ensuring RpA of D mesons in pPb collisions at 5 TeV is a rather subtle balance between cold nuclear effects, equilibration in the QGP droplet and the hadronization mechanism. In our simulation, it shows a suppression for pT less than 3 GeV/c, while for the pT>3 GeV/c one finds an almost constant behavior. Our results are in good agreement with the existing experimental data.
Speaker: Vitalii Ozvenchuk (Subatech)
• 15:00 15:30
Coffee break 30m
• 15:30 16:15
Pre-equilibrium and Initial State Physics: The LHC data at p-Pb collisions (& nPDFs)
Convener: Manoel R. Moldes
• 15:30
The LHC data at p-Pb collisions (& nPDFs) 45m
Speaker: Manoel R. Moldes
• Friday, 31 July
• 09:30 10:30
QCD at High Temperature and Density & Phase Diagram
• 09:30
QCD thermodynamics from lattice simulations 30m
I will present recent results on the QCD equation of state, correlations and fluctuations of conserved charges and the curvature of the phase diagram obtained through lattice simulations. A link to experimental observables from RHIC and the LHC will be discussed.
Speaker: Claudia Ratti
• 10:00
Thermodynamics of Hot and dense matter in resummed perturbation theory 30m
Speaker: Munshi Golam Mustafa
• 10:30 11:00
Coffee break 30m
• 11:00 11:30
Electroweak Probes
• 11:00
Electromagnetic-field induced transports in heavy-ion collisions and cold atoms 30m
Heavy-ion collisions can generate extremely hot/dense medium and extremely strong electromagnetic fields. We discuss some general properties of these fields, including the centrality dependence, collision energy dependence, azimuthal correlations to the matter geometry, etc. Once there appear parity-odd domains in the quark-gluon plasma, the electromagnetic field can induce anomalous tranports. We focus on one newly found anomalous transport, namely, the chiral electric separation effect and its implications in heay-ion collisions. Finally, we discuss the possibility of realizing the anomalous transports in cold atoms.
Speaker: Xu-Guang Huang (Fudan University)
• 11:30 12:00
Jet quenching and energy loss
• 11:30
Radiative corrections to jet quenching in dense and dilute media 30m
Jet measurements in heavy ion collisions from the LHC and RHIC have highlighted the necessity of new theoretical tools to understand the dynamics of jets going through a quark-gluon plasma. Recent developments have shown how the implementation of color decoherence concepts can help understand the main features of jet modification and the importance of the possibly large radiative corrections. Here it is shown how these corrections appear in both dense and dilute media and how the interpolation between the two cases can help us understand the interplay between medium-induced radiation and vacuum-like emissions.
Speaker: Fabio Dominguez (Universidade de Santiago de Compostela)
• 12:30 14:00
Lunch 1h 30m
• 14:00 14:45
Future facilities
• 14:00
Physics at A Fixed-Target ExpeRiment at the LHC: AFTER@LHC 45m
I will review recent ideas put forward in favour of a fixed-target experiment using the proton and lead LHC beams (AFTER@LHC). Connexions with SMOG@LHCb will also be discussed. References: [http://after.in2p3.fr/after/index.php/Recent_published_ideas_in_favour_of_AFTER@LHC][1] [1]: http://after.in2p3.fr/after/index.php/Recent_published_ideas_in_favour_of_AFTER@LHC
Speaker: Jean-Philippe Lansberg (IPN Orsay, Paris Sud U. / IN2P3-CNRS)
• 14:45 17:35
Pre-equilibrium and Initial State Physics
• 14:45
Forward di-jets at the LHC 30m
I am going to overview recent studies of saturation effects in the production of forward dijets in proton-lead collisions at the Large Hadron Collider, using the framework of High Energy Factorizations. Such configurations, with both jets produced in the forward direction, probe the gluon density of the lead nucleus at small longitudinal momentum fraction, and also limit the phase space for emissions of additional jets. The results show significant suppression of the forward dijet azimuthal correlations in proton- lead versus proton-proton collisions. This effect is attributed to stronger saturation of the gluon density in the nucleus than in the proton. Furthermore I will present extensions of the above mentioned framework HEF to account for full CGC effects and hard scale effects related to resummation of logarithms of hard scale. Both of the extensions are crucial from theoretical point of view and are supported by preliminary phenomenological studies.
Speaker: Dr Krzysztof Kutak (Institute for Nuclear Physics Polish Academy of Science)
• 15:15
Coffee break 30m
• 15:45
Has the saturation model found its smoking gun? 30m
With a foundation of almost two decades of theoretical research, the gluon saturation formalism is widely considered a strong candidate to describe the behavior of small-$x$ gluons in high-energy collisions. However, the formalism has proven difficult to test. There is a pressing need for precise numerical results from the saturation formalism to use in comparisons with collider data. Fortunately, recent progress in the $pA\to h+X$ cross section shows that it may be just the kind of precise result the community needs. The calculation of the NLO corrections, starting in 2012, achieved impressive reductions in the theoretical and numerical uncertainties, although the result becomes negative at high $p_\perp$. Still, precise predictions at moderate $p_\perp$ could be key to showing the viability of the saturation model. In this talk, I introduce the recent modifications to the dipole splitting functions that complete the NLO corrections and help offset the negativity observed in earlier results. I'll also present the latest numerical results for the full LO+NLO cross section, including the first comparison with LHC pilot run data. For forward rapidity at both RHIC and the LHC, we have found excellent agreement with the data throughout the range in which the calculation is valid.
Speaker: David Zaslavsky (Penn State University)
• 16:15
Heavy quark pair production in pA collisions at the LHC within the CGC framework 30m
We consider heavy quark pair production in high energy pp and pA collisions from the Color Glass Condensate (CGC) framework. The parton saturation is expected to characterize low-$P_\perp$ spectrum of the heavy quark pair production. Meanwhile, initial soft gluon radiation also can affect the low-$P_\perp$ spectrum. Therefore, in order to study the parton saturation quantatively, both the small-$x$ resummation and the low-$P_\perp$ resummation have to be considered simultaneously. In this talk, a brief review of the CGC framework will be presented first and then we will investigate the low-$P_\perp$ spectrum by considering initial soft gluon emission.
Speaker: Kazuhiro Watanabe (Central China Normal University)