Eduardo Royo
(Universidad de Zaragoza)
01/08/2016, 17:25
Quantum Field Theories of dense, cold matter
Poster
Understanding the role of the $\theta$ parameter in QCD and its
connection with the strong CP problem and axion physics is one of the
major challenges for high energy theorists. Due to the sign problem,
at present only the QCD topological susceptibility is well
known. Using an algorithmic approach that could potentially be
extended to QCD, we study as a first step the $\theta$-dependence...
Ms
Ouraman Hajizadeh
(University of Graz)
01/08/2016, 17:25
Quantum Field Theories of dense, cold matter
Poster
G2-QCD, i.e. QCD with the gauge group SU(3) replaced by the exceptional
group G(2), shares many features with SU(3). But it is accessible at
finite density on the lattice, as it has no sign problem, and at the
same time has a neutron.
Therefore, this theory can sustain in princple neutron star. Using the
equation of state for this theory from lattice simulations, we solve...
Dr
Julien Frison
(KEK Theory Center)
01/08/2016, 17:25
Bulk properties of the quark-gluon plasma
Poster
At $T>T_c$, the topological susceptibility quickly drops down, although the precise speed of this fall is still subject to theoretical debates. It then becomes practically impossible for lattice QCD to handle volumes large enough to allow non-trivial topology and a precise sampling of the sectors involved in the $\theta=0$ vacuum. We present a new method applicable to the computation of the...
Prof.
Gert Aarts
(Swansea University)
01/08/2016, 17:25
Transport properties and probes
Poster
Unlike mesons, lattice studies of baryons at finite temperature are very
limited. We present results for baryon correlators and spectral functions
across the deconfinement transition, using the FASTSUM 2+1 flavour
ensembles as well as results with free lattice fermions.
Dr
Mathias Wagner
(NVIDIA)
01/08/2016, 17:25
Poster
Analysis tasks in Lattice QCD thermodynamics often requires solving linear equations for multiple right hand sides for a constant gauge field. Recently deflation methods have become more widely used and proven to be very efficient. They however do require the calculation and storing of eigenvectors which is either not always feasible or suffer from high setup costs. We present results for an...
Mr
Haitao Shu
(CCNU)
01/08/2016, 17:25
Transport properties and probes
Poster
We present our most updated results on the charmonium correlation and spectral functions. The correlation functions are obtained using the clover improved Wilson fermions on quenched lattices with spatial size fixed to 192. And temporal sizes of these lattices are chosen to be 96, 64, 56, 48 and 32 corresponding to 0.73, 1.1, 1.25, 1.5 and 2.2 Tc. We perform a detailed analysis of these...
Mr
Sheng-Tai Li
(Central China Normal University)
01/08/2016, 17:25
QCD phase diagram
Poster
We present our recent results on the chiral phase transition in 2+1 flavor QCD on lattices with temporal extent $N_{\tau} = 6$. We have performed lattice QCD simulations using the Highly Improved Staggered Quarks with 5 different values of pion masses, i.e. 160, 140, 110, 90, 80 MeV in a temperature window from 140 MeV to 170 MeV. We have analyzed the universal scaling behaviour of the chiral...
Dr
Savvas Zafeiropoulos
(Goethe University Frankfurt)
01/08/2016, 17:25
Quantum Field Theories of dense, cold matter
Poster
We study a Random Matrix Model for QCD at finite density via Complex Langevin dynamics. This model has a phase transition to a phase with non-zero baryon density. We study the convergence of the algorithm as a function of the quark mass and the chemical potential and focus on two main observables: the baryon density and the chiral condensate. As expected, for simulations close to the chiral...
Mr
Francesco Sanfilippo
(University of Southampton)
01/08/2016, 17:25
Bulk properties of the quark-gluon plasma
Poster
One of the greatest achievement of lattice QCD is the numerical determination of the confinement potential between pairs of static quarks, as well as the measurement of the shape of the color-flux tube connecting them. In this talk I will present how this is modified in the presence of a magnetic field.
Akihiro Shibata
(Computing Research Center, KEK)
01/08/2016, 17:25
QCD phase diagram
Poster
The dual superconductivity is a promising mechanism for quark confinement. We have presented a new formulation of the Yang-Mills theory on the lattice, and pointed out that the $SU(3)$ Yang-Mills theory has a new way of reformulation using new field variables (minimal option), in addition to the conventional option adopted by Cho, Faddeev and Niemi (maximal option). In the preceding...
Dr
Anthony Francis
(York University)
01/08/2016, 17:25
Transport properties and probes
Poster
We present results on the isovector vector channel spectral functions at vanishing momentum across the deconfinement phase transition in dynamical $n_f=2$ lattice QCD. Using Wilson-Clover fermions the calculations are carried out with a vacuum pion mass of $\simeq 270$MeV at the temperatures $T/T_c=0.156, 0.8, 1.0, 1.25$ and 1.67. The spectral functions are reconstructed from local-conserved...
Prof.
Ion-Olimpiu Stamatescu
(I.T.P., University Heidelberg)
01/08/2016, 17:25
Quantum Field Theories of dense, cold matter
Poster
Zeroes in the fermionic determinant induce poles in the drift
of the Langevin equation. We here study their effect on Complex Langevin
simulations in an effective model related to QCD in the limit of heavy quarks
and large chemical potential. The latter was defined long ago by one of the authors and
used thereafter in various contexts.
We approach in this way a
quantitative...
Dr
Saumen Datta
(Tata Institute of Fundamental Research)
01/08/2016, 17:25
Transport properties and probes
Poster
The deconfinement transition is typically studied using the Polyakov loop,
which needs renormalization. We look at the renormalization of Polyakov loop
using Wilson flow, for both quenched and $N_f=2$ QCD. We also investigate
some observables related to the Polyakov loop that has been suggested, and
the behavior of the gluon condensate across the transition.
Mr
Francesco Capponi
(Plymouth University)
01/08/2016, 17:25
Transport properties and probes
Poster
We present an update about our program for the non perturbative renormalization of the energy momentum tensor. Our strategy is based on probing suitable lattice Ward identities with observables computed along the gradient flow. This set of identities exhibits many interesting qualities, resulting from the UV finiteness of flowed composite operators, and can be used to measure the...
Mr
Felix Ziegler
(Heidelberg University)
01/08/2016, 17:25
Poster
Studying the topological properties of the QCD vacuum on the lattice, observables such as the gauge action density are blurred by short distance fluctuations at scales of the order of the lattice spacing.
To extract the physical content from the mentioned configurations, those have to be treated using smoothing methods such as cooling or the Wilson flow which have been investigated...
Dr
Benjamin Jaeger
(Swansea University)
01/08/2016, 17:25
Quantum Field Theories of dense, cold matter
Poster
Complex Langevin methods have been successfully applied in theories that suffer from a sign problem such as HDQCD. We present and illustrate a novel method that ensures that Complex Langevin simulations stay close to the SU(3) manifold, which lead to correct and improved results in the framework of HDQCD and pure gauge simulations. Applying the same technique in fully dynamical QCD simulations...
Dr
Bastian Brandt
(University of Frankfurt)
01/08/2016, 17:25
QCD phase diagram
Poster
We study the strength of the anomalous breaking of the $U_A(1)$ symmetry in the chiral limit of two-flavour QCD at the transition temperature using the difference of the pseudoscalar and scalar iso-vector screening masses. To this end we use simulations with non-perturbatively $O(a)$-improved Wilson fermions for three different pion masses in the range of 200-550MeV on lattices with a temporal...
Mr
Tobias Rindlisbacher
(ETH Zürich)
01/08/2016, 17:25
Quantum Field Theories of dense, cold matter
Poster
We recently proposed a new type of worm algorithm for simulating the CP(N-1) model at finite density in a dual representation based on flux-variables. Here we continue by discussing how a topological term can be incorporated into our dual formulation.
Dr
pietro giudice
(University of Muenster)
01/08/2016, 17:25
Quantum Field Theories of dense, cold matter
Poster
We study two-color QCD with two flavours of Wilson fermion as a
function of quark chemical potential and temperature.
Recent results are presented and the phase diagram is discussed.
Mr
Dean Thomas
(Swansea University)
01/08/2016, 17:25
QCD phase diagram
Poster
Topology driven techniques are an important and established tool in volume visualisation computer graphics; however, they have yet to see widespread adoption in the lattice QCD community. In comparison to traditional isosurfacing algorithms they offer a number of advantages including faster rendering speeds and enhanced data exploration possibilities. The ability to summarise the topology of...
Dr
Szabolcs Borsanyi
(University of Wuppertal)
01/08/2016, 17:25
QCD phase diagram
Poster
We calculate the QCD cross-over temperature, the equation of state and fluctuations of conserved charges at finite density by analytical continuation from imaginary to real chemical potentials. Our calculations are based on new continuum extrapolated lattice simulations using the 4stout staggered actions with a lattice resolution up to Nt=16. The simulation parameters are tuned such that the...
