Mr
Mario Schroeck
(Universitaet Graz)
5/7/12, 11:30 AM
Chiral symmetry breaking in Quantum Chromodynamics is associated with the low lying spectral modes of the Dirac operator according to the Banks-Casher relation. Here we study how removal of a variable number of low lying modes from the valence quark sector affects the masses of the first excited states of baryons and mesons in two flavor lattice QCD.
Valentina Verduci
(University of Graz)
5/7/12, 12:00 PM
We study positive and negative parity states of the nucleon, with particular interest in the parity reversal pattern of the Roper resonance. We investigate the isospin 1/2 channel of the pion-nucleon scattering on the lattice, including meson-nucleon interpolators. The distillation method makes the computation of disconnected diagrams affordable, while the variational method is used to extract...
Daniel Maitre
(CERN)
5/7/12, 6:30 PM
Recent progress in the calculation of Next-To-Leading order observables in perturbative QCD are presented, with a focus on results from so-called unitarity techniques for high multiplicity processes.
Ydalia Delgado Mercado
(Karl-Franzens University)
5/8/12, 9:00 AM
We study effective theories for QCD at non-zero temperature and finite chemical potential, using local Polyakov loops as the degrees of freedom. The sign problem is solved by exactly mapping the partition sum to a sum over flux variables with only real and positive weights, and the theory is then accessible to Monte Carlo Techniques. We determine the phase diagram as a function of the...
Mr
Sandeep Chatterjee
(PhD student)
5/8/12, 9:30 AM
We consider the $(2+1)$ flavor Polyakov Quark Meson Model (PQM) and study the effect of including fermion vacuum fluctuations on the thermodynamics and phase diagram. The variation of the thermodynamic quantities across the phase transition region becomes smoother.
This results in better agreement with the lattice QCD (LQCD) data. The critical end point is pushed into higher values of the...
Paulo Silva
(U)
5/8/12, 10:00 AM
We study the Landau gauge gluon propagator at zero and finite temperature using lattice simulations. Particular attention is given to the finite size effects and to the infrared behaviour. Furthermore, the modeling of the lattice data is discussed.
Mrs
Elina Seel
(ITP Frankfurt University)
5/8/12, 11:00 AM
The thermodynamics of the O(N) model in 1+1 dimensions is studied applying the auxiliary field method. In order to compute the thermodynamical quantities we apply the CJT formalism within the Hartree-Fock approximation extended by sunset diagrams. The numerical results for the renormalized mass of the scalar particles, the pressure, the trace anomaly and the energy density are presented and...
Mr
Stanislaus Janowski
(Institute for Theoretical Physics, J. W. Goethe University)
5/8/12, 6:30 PM
We present a two-flavour linear sigma model with global chiral
symmetry and (axial-)vector mesons as well as an additional glueball
degree of freedom. We study the structure of the well-established
scalar resonances f0(1370) and f0(1500): by a
fit to experimentally
known decay widths we
find that f0(1370) is predominantly a
quark-antiquark state and f0(1500) is predominantly a...
Pedro Costa
(Physics Department of the University of Coimbra)
5/9/12, 9:00 AM
We investigate the phase diagram of the so-called Polyakov–Nambu–Jona-Lasinio model at finite temperature and nonzero chemical potential. The calculations are performed in the framework of the PNJL Lagrangian in the light and strange quark sector (u,d,s) which includes the 't Hooft instanton induced interaction term that breaks the axial symmetry, and the quarks are coupled to the (spatially...
Stefano Lottini
(Goethe Universitaet, Frankfurt am Main)
5/9/12, 9:30 AM
We examine the phase diagram of hadronic matter when the number of colours Nc, as well as temperature and density, are varied. We show that in this regime a new percolation phase transition is possible, and examine the implications of this transition for extrapolations to physical QCD of the large-Nc limit.
David Ibáñez Gil de Ramales
(University of Valencia)
5/9/12, 10:00 AM
Recent large-volume lattice simulations have established that, in the Landau gauge, the gluon propagator is infrared-finite.
The most natural way to explain this observed finiteness is the generation of a nonperturbative, momentum-dependent gluon mass.
Such a mass may be generated without compromising the gauge-invariance of the fundamental QCD Lagrangian
by employing the famous...
Walaa ESHRAIM
5/9/12, 11:00 AM
We present the extension of
the globally chirally invariant N_f=3 linear sigma model with
vector and axial-vector degrees of freedom to N_f=4. We
calculate the masses of axial- vector mesons from the extended
model and present it.
Mr
Denis Parganlija
(TU Vienna, ITP)
5/9/12, 11:30 AM
Scalar mesons have been one of the most hotly debated issues of
low-energy QCD for decades. Experimental data show the existence of six scalar isosinglet states in the region below 1 GeV -- next to the famous sigma meson, there are five states with the same quantum numbers but higher energies than the energy of the sigma. If we consider u and d quarks as degenerate and work in a theoretical...
Dr
Aneta Iordanova
(University of California, Riverside)
5/10/12, 9:00 AM
The PHENIX experiment has produced an extensive array of measurements in heavy ion collisions in order to study the created strongly interacting medium. This medium is seen to modify the properties of many global and high-momentum observables; a strong suppression relative to that expected from p+p collisions is observed. The medium forms after the initial hard-scattering of partons, which...
Sonia Kabana
5/10/12, 9:30 AM
We present some highlights of recent results from STAR experiment at RHIC. Selected topics from results on heavy quarkonia production, collectivity and their energy and system dependence are presented from the experiments heavy ion program.
Marina Marinkovic
(Humboldt University Berlin)
5/10/12, 11:30 AM
Lattice QCD is a first-principle computational tool to describe the properties of hadron spectrum and decay modes, which allows for precision tests of the Standard Model. The algorithm of choice for lattice QCD simulations is known as the Hybrid Monte Carlo (HMC) algorithm. I am going to discuss recent algorithmic and implementation improvements which lead to a better scaling of the new highly...
Rene Bellwied
(University of Houston (US))
5/10/12, 5:00 PM
Recent work on in-medium hadronization in the non-equilibrated
fragmentation process has been followed up by studies on bound state
formation in the equilibrated deconfined matter as described by lattice
QCD. Through the comparison to PNJL model calculations we find
evidence for an extended phase of mixed degrees of freedom. The
extracted hadron formation probability exhibits flavor and...
Ioannis Bouras
(University of Frankfurt a.M.)
5/10/12, 6:30 PM
Using a microscopic transport model we investigate the evolution of conical structures originating from the supersonic projectile moving through the hot matter of ultrarelativistic particles. Using different scenarios for the interaction between projectile and matter, and different transport properties of the matter, we study the formation and structure of Mach cones. Especially, a dependence...
Marco Cardoso
(Instituto Superior Técnico)
5/10/12, 7:00 PM
In this work we compute the color fields in the mediator plane between a static quark and a static antiquark using quenched lattice QCD.
In special, we see the effect of the quark-antiquark distance on this fields. To obtain this results an improved multihit technique is developed
and an extend smearing technique is used. The results for the fields are fitted with different models and in...
Dionysis TRIANTAFYLLOPOULOS
5/11/12, 9:00 AM
At high energy and/or for large atomic numbers the wave-function of a generic hadron is dominated by gluon modes and saturates. This is the Color Glass Condensate (CGC) and it can manifest itself in Deep Inelastic Scattering and in Proton-Proton and Heavy Ion Collisions. The evolution of the CGC with energy satisfies a Renormalization Group Equation, the JIMWLK equation. We review the theory...
Ms
Márcia Quaresma
(LIP-Lisbon)
5/11/12, 10:00 AM
The Parton Distribution Functions (PDFs) and the spin structure of the nucleon are important topics studied by COMPASS in Semi-Inclusive Deep Inelastic Scattering. The Drell-Yan process is a complementary way to access the Transverse Momentum Dependent PDFs (TMD PDFs), using a transversely polarized target.
Studying the angular distributions of dimuons from the Drell-Yan reactions in the...
Prof.
Brigitte Hiller
(Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, P-3004-516 Coimbra, Portugal)
5/11/12, 11:00 AM
The topic I would like to present is the effect of chiral multiquark interactions (with emphasis on the new eight quark terms) on the temperature versus baryonic chemical potential phase diagram of this extended Nambu Jona Lasinio model of QCD. The talk is mainly based on the works:
The Phase diagram for the Nambu-Jona-Lasinio model with 't Hooft and eight-quark interactions.
B. Hiller, J....
Mr
Vladimir Sauli
(DTP, NPI Rez near Prague)
5/11/12, 12:00 PM
When generalizing recent various quantum mechanical models of $c-\bar{c}$ states to Quantum Filed theoretical approach based on BSE one is faced to the solutions that do not exist in non-relativistic limit. Mainly, there is unexpected doubling of the spectrum when comparing to the spectrum expected or known from the experiments as well as the ones known from the solution of the...
Dr
Marcus Bluhm
(Laboratoire SUBATECH)
5/11/12, 5:00 PM
The knowledge of transport coefficients of the Quark-Gluon Plasma
(QGP) gives fundamental insights into the nature of strongly
interacting matter under extreme conditions. By means of
relativistic heavy-ion collisions, these properties are intended
to be experimentally revealed, providing also information about
the structure of the produced hot matter. One of the remarkable...
Dr
Marlene Nahrgang
(SUBATECH, Nantes & FIAS, Frankfurt)
5/11/12, 5:30 PM
In thermodynamics system the correlation length of fluctuations of the order parameter diverges at a critical point. This is the basis of expecting large event-by-event fluctuations for heavy-ion collisions that reach in the critical region. Heavy-ion collisions are however very small and dynamic systems, which at most reach local thermal equilibrium. The effect of critical slowing down is...
diana nicmorus
(Facility for Antiproton and Ion Research in Europe GmbH)
5/11/12, 6:30 PM
The new international accelerator facility FAIR under construction in Darmstadt aims at studying matter at atomic, nuclear, and hadronic levels.
I will present different aspects of the current status of the Facility for Antiproton and Ion Research. I will discuss the focus of the experiments at FAIR and the associated theory in hadron physics, nuclear structure and compressed nuclear matter...
Tord Johansson
(Uppsala University)
5/11/12, 7:00 PM
The PANDA experiment is one of the major projects at the upcoming Facility for Antiproton and Ion Research (FAIR) facility in Darmstadt, Germany. It will study interactions between antiprotons and protons or nuclei in the momentum range of 1.5 GeV/c to 15 GeV/c with a 4pi state-of-the-art detector. The purpose of the experiment is to learn about fundamental aspects of the strong interaction in...