Conveners
Deconfinement: D1a
- Aleksi Vuorinen (University of Helsinki)
Deconfinement: D1b
- Aleksi Vuorinen (University of Helsinki)
Deconfinement: D2a
- Edmond Iancu (IPhT)
Deconfinement: D2b
- Edmond Iancu (IPhT)
Deconfinement: D3a
- Peter Petreczky (BNL)
Deconfinement: D3b
- Peter Petreczky (BNL)
Deconfinement: D5a
- Yiota Foka (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))
Deconfinement: D5b
- Yiota Foka (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))
We will update our continuum extrapolated result on the chiral
crossover temperature in QCD with (2+1)-flavor and physical quark
masses. Results are based on calculations with Highly improved
Staggered Quarks (HISQ) on three different lattices sizes (Nฯ=6,8,12).
We systematically study all chiral second-order susceptibilities that
diverge in the ciral limit. From a Taylor expansion of...
We calculate the equation of state at high temperatures in 2+1 flavor QCD using the highly improved staggered quark (HISQ) action. We study the lattice spacing dependence of the pressure at high temperatures using lattices with temporal extent (N_\tau= 6,\ 8,\ 10) and (12) and perform continuum extrapolations.
We also give a continuum estimate for the equation of state up to temperatures...
In this talk I will present our strategy for a fully non-perturbative determination of the equation of state (EoS) of QCD from low (T~100 MeV), up to very high temperature (T~100 GeV). The key ingredient for such determination is the lattice formulation of QCD in a moving reference frame. I shall discuss in particular how the set-up allows for a neat determination of the entropy density from...
We analyze the role of high spin hadronic states in the correlation functions of conserved charges such as baryon and electric charge and strangeness at finite temperature. The corresponding integrated quantities correspond to (global) thermal fluctuations and their related susceptibilities are well known from lattice QCD. At the local level we conjecture an interesting duality between the...
The formation of a QGP in heavy ion collisions and the collective/hydrodynamic expansion of the created medium are well established and reasonably well understood. In particular, looking at anisotropy of the final-state distribution of particles produced in A-A collisions, it is now established that the QGP behaves like a nearly perfect fluid with a shear viscosity close to the KSS bound. This...
In the collision of nuclei at high energies the produced matter reinteracts and form a plasma which ultimately equilibrates and exhibits collective hydrodynamic flow. While a general theory of the equilibration process has been outlined previously, there were no practical frameworks to smoothly connect the early gluon production in classical field simulations with hydrodynamic simulations of...
Due to absence of expansion transverse to the beam direction, Bjorken flow is unable to describe certain observables in heavy ion collisions such as transverse momentum spectra of final hadrons. This caveat has motivated introduction of analytical relativistic hydrodynamics(RH) solutions with transverse expansion, in particular 3+1 self-similar and Gubser flows. Inspired by recently found...
A new framework for relativistic fluid dynamics of particles with spin 1/2 is presented. It is based on the conservation laws for baryon number, energy and momentum, and angular momentum. The conservation laws lead to hydrodynamic equations for the charge density, local temperature, and fluid velocity, as well as for the spin polarization tensor. The resulting set of differential equations...
We first review transverse-momentum dependent (TMD) gluon distributions at small $x$ and their relation to unintegrated gluon distributions in the Color Glass Condensate (CGC) theory. We then explore several applications of this connection relevant for studying gluon saturation at small $x$. For instance, based on the equivalence between the TMD factorization approach and the CGC cross section...
Reaching next-to-leading order accuracy in perturbative calculations of particle production in QCD at high energy is essential for reliable phenomenological applications. In recent years, the Color Glass Condensate effective theory (the natural framework for such calculations) has indeed been promoted to NLO accuracy. However, the first NLO calculation of single-inclusive hadron production met...
I discuss some features of entanglement between the fast valence modes and the soft gluons in high energy hadronic scattering. Production entropy for the ensemble of events as well as for a single event is discussed.
In recent years, there have been important advances in understanding the far-from-equilibrium dynamics in gauge and scalar field theories. For non-Abelian gauge systems, the combination of different methods led to the development of a consistent weak-coupling thermalization picture in ultrarelativistic heavy-ion collisions, from the initial Glasma state to the onset of hydrodynamics, and the...
Hard scattered quarks and gluons have been used extensively as multi-scale probes of the strongly interacting medium produced in relativistic heavy ion collisions. The high statistics data recorded in the Large Hadron Collider and large transverse momentum reach due to the high nucleon-nucleon center-of-mass energy have opened a new era for the understanding of the mechanism of parton-medium...
Hard processes in heavy-ion collisions, in particular those involving the production of jets in the final-state, can potentially serve as well-constrained probes of a hot and dense QCD medium. At high-energies, radiation stimulated via interactions with the medium, that is subject to LPM interference effects, control the amount of energy radiated away from the jet constituents, providing a...
It is well known that the multiple interactions of a hard probe with the dense quark-gluon plasma results in the โmedium-inducedโ radiation of soft gluon, responsible e.g. for jet energy loss. Such an emission is computed using the BDMPS-Z formalism which has since been generalised to include multiple medium induced emissions. To get a complete picture of the evolution of a jet in a dense...
We will report on recent progress in the determination of spectral and transport properties of heavy quarks. Combining continuum extrapolated correlation functions in a pure SU(3) plasma and spectral reconstructions constrained by phenomenological and perturbative input, we study thermal modifications of quarkonium spectra and improve the determination of heavy quark diffusion coefficients.
I will review recent developments in the theoretical description and understanding of multi-particle correlations in collisions of small projectiles (p/d/3He) with heavy nuclei (Au, Pb), as well as in proton+proton collisions. A main question is, whether the physical processes responsible for the observed long range rapidity correlations and their azimuthal structure are the same in small...
We present the correct form of the nonequilibrium viscous correction to the phase space density in the relaxation time approximation that properly takes into account the space-time dependence of the thermal mass. We also investigate the impact the correction has on the bulk viscosity. This correction automatically satisfies the Landau matching condition and energy-momentum conservation. It...
Recent advancements in multi-parameter model-to-data comparison have provided notable constraints on the temperature dependence of the shear viscosity over entropy density ratio $\eta/s$ in the matter produced in the Pb+Pb collisions at the LHC. The results of the Bayesian analysis with a flexible initial state parametrization [1,2] support a linear temperature dependence of $\eta/s$ found in...
We critically compare thermodynamic and kinetic approaches, that have been recently used to study relations between the spin polarization and fluid vorticity in systems consisting of spin-1/2 particles. The thermodynamic approach refers to general properties of global thermal equilibrium with a rigid-like rotation and demonstrates that the spin-polarization and thermal-vorticity tensors are...
We study the thermodynamics of hadronic matter using the hadron resonance gas model where the repulsive interactions between baryons are modeled using the mean field approach.
We have shown [1] that repulsive interactions are especially important when considering the higher order fluctuations. We now extend the treatment of [1] to cover not only ground state baryons but heavier resonances...
In this talk I shall discuss how the S-matrix formalism can be applied to study the thermal properties of interacting hadrons.
The approach allows a consistent treatment of broad resonances and purely repulsive channels, while correctly implementing the constraints from the chiral perturbation theory. This provides a useful framework for identifying the limitations of the Hadron Resonance...
The nature of chiral symmetry restoration and the identification of its correct pattern in terms of $O(4)$ and $U(1)_A$ symmetries are central problems for our present understanding of the QCD phase diagram, currently explored in lattice simulations and heavy-ion collisions. We will present a theoretical analysis based on Ward Identities for the full scalar/pseudoscalar $U(3)$ meson...
I will discuss the current state of perturbation theory of the cold and dense QCD thermodynamics. Alongside, I explain a method of handling the infrared degrees of freedom of the theory using Hard Thermal Loop approximations, suitable for the computation of the non-analytic terms of the pressure. By making use of this framework, I will present the computation of a new term, the leading,...
We present the final results from a multi-year [1,2] study of the in-medium spectral properties of heavy quarkonium bound states on the lattice. In this work we combine high statistics N_f=2+1 ensembles from the HotQCD collaboration with the effective theory NRQCD and improved Bayesian spectral reconstruction methods. We corroborate earlier findings on the sequential suppression of quarkonium...
We present recent computations of loop functions in thermal QCD
like the Polyakov loop, correlators of Polyakov loops and Wilson lines,
and the cyclic Wilson loop.
We discuss divergences and how to renormalize them.
Finally we compare with lattice data.
A Lindblad equation for the evolution of heavy quarkonia in QGP has recently been derived from potential non-relativistic QCD (pNRQCD) and open quantum system framework. We derive the classical limit of the evolution equations for color-singlet and color-octet quarkonia states. Within the classical approximations, we are able to write the evolution equations respectively as a Langevin equation...
Charmonium production is a crucial observable in pp and A-A collisions.
Studies on charmonium production in pp collisions can help to understand both fundamental perturbative QCD processes $i.e.$ the initial charm-quark pair production, as well as hadronization mechanisms $i.e.$ the subsequent binding into a charmonium state. $J/\psi$ measurements as a function of multiplicity can help to...
Measurements on dielectrons (electron-positron pairs) produced in ultra-relativistic heavy-ion collisions (HIC) allow the study of the electromagnetic radiation that is emitted through the whole evolution of the system and that is not affected by final state interactions. Through the study of dielectrons at midrapidity one can investigate different phenomena by taking advantage of the degree...
The main goal of the ALICE experiment at the LHC is to study the strongly-interacting hot anddense matter created in ultra-relativistic heavy-ion collisions. In this context, the measurement of strangeness production is one of the most powerful tools to investigate the thermal properties of the deconfined state of QCD matter known as Quark-Gluon Plasma (QGP). Smaller collision systems, such as...
We present the recent results on the confinement/deconfinement transition in lattice SU(2) QCD with two flavors of quarks at finite quark density and zero temperature. In the region $\mu_q$ โผ 1000 MeV we observe the confinement/deconfinement transition which manifests itself in rising of the Polyakov loop and vanishing of the string tension $\sigma$. After the deconfinement is achieved at...
QCD vacuum can be treated as a series of energetically equivalent, but topologically distinct sectors. The rate of transitions between various topological sectors is determined by the sphaleron diffusion rate $\Gamma_{CS}$. This quantity is given by the limits of zero frequency and zero momentum of the correlator of topological charge density. Sphaleron diffusion rate is very similar to such...
We study the Landau gauge quark propagator, at finite temperature, using quenched lattice simulations. Special focus is given to the behaviour of the momentum space form factors across the confinement-deconfinement phase transition.
We compute the effective potential for the Polyakov loop in a pure SU(N) gauge theory beyond two-loop order. We introduce a new approach using the Poisson resummation formula, which is well suited to compute thermal sums/integrals with non-trivial holonomy. We discuss the implications for phenomenology with three colors, and theoretical questions at large N.
