Nuclear and Quark Matter Seminar 2014
26 February 2014, 13:15 - EMMI/KBW Seminar room 5.29
Properties of the QCD phase diagram from chemical freeze-out
Stefan Floerchinger - CERN
Heavy ion collisions provide a great opportunity to learn about the chiral, thermodynamic and transport properties of QCD and in particular about its phase diagram. Chemical freeze-out temperatures from statistical fits to particle abundances are seen as an indication of the chiral phase transition or crossover temperature at small baryon densities as measured at RHIC and LHC energies. In contrast, at small collision energies and high baryon chemical potential the temperatures correspond to fixed baryon number density. The physics of chemical freeze-out is reviewed in both cases, with an emphasis on the region of higher baryon number density where the thermodynamic and chiral properties are rather well understood from the nuclear droplet model.
26 March 2014, 13:15 - EMMI/KBW Seminar room 5.029
Phase transitions in fluid dynamical simulations of nuclear collisions
Jan Steinheimer - FIAS Frankfurt
I will discuss a fluid dynamical model, augmented with a finite-range term, capable of describing the dynamics of the mechanically unstable spinodal region of the QCD phase diagram. For head-on relativistic lead-lead collisions that bring the bulk of the system into the mechanically unstable spinodal region, the density irregularities are being amplified significantly. High order moments of the baryon number density distributions are significantly amplified and clusters of quark matter with a characteristic baryon number are enhanced. I will also discuss the sensitivity of several observables on the instabilities, associated with the first-order phase co-existence.
9 April 2014, 10:00 - EMMI/KBW Seminar room 5.29
Heavy Quarkonium from the Lattice
Alexander Rothkopf - Uni Heidelberg
Heavy quarkonium suppression in relativistic heavy-ion collisions is a well established phenomenon, observed both at RHIC and LHC. In order to interpret these findings, a thorough understanding of the formation of bound states of heavy quarks, as well as their real-time evolution in a quark-gluon plasma is called for. The description of quarkonium is facilitated by the separation between the mass of the heavy quark and the medium partons. It allows us to use simple quantum mechanics, where the QQbar is represented by a wavefunction, governed by a Schrödinger equation with an appropriate in-medium potential. Modern lattice QCD methods complement this approach by providing non-perturbative information on the interactions between heavy quarks and the surrounding relativistic medium. I.e. they can be used to infer the values of the potential or directly of the spectrum of quarkonium at any desired temperature. Here we present recent advances in setting up a consistent real-time description of heavy quarkonium in a thermal medium from first principles. We emphasize that a Schrödinger equation can be obtained from QCD, show how the potential can be extracted from lattice QCD simulations and interpret the complex values of the in-medium potential as loss of coherence of the heavy quarkonium on its way towards thermal equilibrium.
4 June 2014, 13:15 - EMMI/KBW Lecture Hall (1.17)
Jet Quenching at the LHC
Korinna Zapp - CERN
Highly energetic quarks and gluons fragment into collimated sprays of hadrons, so-called jets, with a characteristic structure. In ultra-relativistic heavy ion collisions the rates as well as the shapes of jest get modified due to re-scattering. I will give a general introduction to jets in p+p and A+A collisions, introduce theoretical approaches and give a short overview over recent LHC data.
26 June 2014, 15:45 - EMMI/KBW Seminar room 5.032
The STAR Heavy Flavor Tracker and new ideas about gating grids in GEM-based TPCs
Howard Wieman - LBNL
9 July 2014, 13:15 - EMMI/KBW Lecture Hall (1.17)
From hadrons to partons and back
Elena Bratkovskaya - FIAS Frankfurt
We study 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 hadronic collision dynamics in the final reaction phase. We investigate the equilibrium properties of strongly-interacting infinite parton-hadron matter in terms of transport coefficients, such as shear and bulk viscosity, electric and heat conductivity in comparison to lattice QCD results. Furthermore, the 'highlights' of the latest results on electromagnetic and collective flow observables from heavy-ion collisions will be presented.
24 September 2014, 11:00 - EMMI/KBW Lecture Hall (1.17)
Global collective flow in heavy ion reactions from the beginnings to the future
Laszlo Csernai - University of Bergen, Norway
Fluid dynamical models preceded the first heavy ion accelerator experiments, and led to the main trend of this research since then. In recent years fluid dynamical processes became a dominant direction of research in high energy heavy ion reactions. The Quark-Gluon Plasma formed in these reactions has low viscosity, which leads to significant fluctuations and turbulent instabilities. One has to study and separate the collective and fluctuating flow effects, but this is not done yet in a systematic way. Here we present the most interesting collective flow instabilities, their origins, their possible ways of detection and their experimental separation form random fluctuations arising from the randomness of the initial configuration in the transverse plane.
5 November 2014, 13:15 - EMMI/KBW Lecture Hall (1.17)
Towards the Physics Programme at NICA
David Blaschke - University of Wroclaw and JINR Dubna
Since 5 years the community is submitting contributions to the White Paper for NICA (Nuclotron-based Ion Collider fAcility), the flagship project of JINR Dubna, being devoted to the search for a mixed phase between hadronic and quark matter in the QCD phase diagram. We report about the ongoing process of selecting the most promising ideas for that goal which shall then be promoted towards a scientific programme for that facility. A few new developments in theory and simulations which were triggered by this process will be emphasized.
12 November 2014, 12:45 - EMMI/KBW Lecture Hall (1.17)
Fishing for the QCD Phase transition
Volker Koch - LBNL & EMMI
In this talk I will discuss the present status and some future outlook of the quest to identify a possible QCD phase transition.
A. Andronic, R. Holzmann, V. Friese
Last modified: Mon Jul 21 11:13:27 CEST 2014