73 research outputs found
The chiral transition as an Anderson transition
At low temperature the low-lying QCD Dirac spectrum obeys random matrix
statistics. Recently we found that above the lowest part of the
spectrum consists of localized modes that obey Poisson statistics. An
interesting implication of this is that as the system crosses from
above, the spectral statistics at changes from Poisson to random
matrix. Here we study this transition and its possible implications for the
finite temperature transition of QCD-like theories.Comment: 7 pages, 4 figures, Contribution to the 32nd International Symposium
on Lattice Field Theory (Lattice 2014), 23-28 June 2014, Columbia University,
New York, NY, US
Is there a flavor hierarchy in the deconfinement transition of QCD?
We present possible indications for flavor separation during the QCD
crossover transition based on continuum extrapolated lattice QCD calculations
of higher order susceptibilities. We base our findings on flavor specific
quantities in the light and strange quark sector. We propose a possible
experimental verification of our prediction, based on the measurement of higher
order moments of identified particle multiplicities. Since all our calculations
are performed at zero baryochemical potential, these results are of particular
relevance for the heavy ion program at the LHC.Comment: 5 pages, 3 figures, revte
Continuum EoS for QCD with Nf=2+1 flavors
We report on a continuum extrapolated result [arXiv:1309.5258] for the
equation of state (EoS) of QCD with dynamical quark flavors. In this
study, all systematics are controlled, quark masses are set to their physical
values, and the continuum limit is taken using at least three lattice spacings
corresponding to temporal extents up to . A Symanzik improved gauge and
stout-link improved staggered fermion action is used. Our results are available
online [ancillary file to arXiv:1309.5258].Comment: Conference proceedings, 7 pages, 4 figures. Talk presented at 31st
International Symposium on Lattice Field Theory (LATTICE 2013), July 29 -
August 3, 2013, Mainz, German
Static quark-antiquark pair free energy and screening masses: continuum results at the QCD physical point
We study the correlators of Polyakov loops, and the corresponding gauge
invariant free energy of a static quark-antiquark pair in 2+1 flavor QCD at
finite temperature. Our simulations were carried out on = 6, 8, 10, 12,
16 lattices using a Symanzik improved gauge action and a stout improved
staggered action with physical quark masses. The free energies calculated from
the Polyakov loop correlators are extrapolated to the continuum limit. For the
free energies we use a two step renormalization procedure that only uses data
at finite temperature. We also measure correlators with definite Euclidean time
reversal and charge conjugation symmetry to extract two different screening
masses, one in the magnetic, and one in the electric sector, to distinguish two
different correlation lengths in the full Polyakov loop correlator. This
conference contribution is based on the paper: JHEP 1504 (2015) 138Comment: 7 pages, 4 figures. Talk presented at the 33rd International
Symposium on Lattice Field Theory (Lattice 2015), 14-18 July 2015, Kobe
International Conference Center, Kobe, Japa
QCD transition temperature: full staggered result
We conclude our investigations on the QCD cross-over transition temperatures
with 2+1 staggered flavours and one-link stout improvement. We extend our
previous two studies [Phys. Lett. B643 (2006) 46, JHEP 0906:088 (2009)] by
choosing even finer lattices (N_t=16) and we work again with physical quark
masses. These new results [for details see JHEP 1009:073,2010] support our
earlier findings. We compare them with the published results of the hotQCD
collaboration. All these results are confronted with the predictions of the
Hadron Resonance Gas model and Chiral Perturbation Theory for temperatures
below the transition region. Our results can be reproduced by using the
physical spectrum. The findings of the hotQCD collaboration can be recovered
only by using a distorted spectrum. This analysis provides a simple explanation
for the observed discrepancy in the transition T between our and the hotQCD
collaborations.Comment: presented at the XXVIII. International Symposium on Lattice Field
Theory, June 14-19,2010, Villasimius, Sardinia Ital
Recent results on the Equation of State of QCD
We report on a continuum extrapolated result (arXiv:1309.5258) for the
equation of state (EoS) of QCD with dynamical quark flavors and
discuss preliminary results obtained with an additional dynamical charm quark
(). For all our final results, the systematics are controlled, quark
masses are set to their physical values, and the continuum limit is taken using
at least three lattice spacings corresponding to temporal extents up to
.Comment: Conference proceedings: The 32nd International Symposium on Lattice
Field Theory - Lattice 2014, June 23-28, 2014, Columbia University, New York,
New Yor
The QCD equation of state and the effects of the charm
We present an update on the QCD equation of state of the Wuppertal-Budapest
Collaboration, extending our previous studies [JHEP 0601 (2006) 089, JHEP 1011
(2010) 077]. A Symanzik improved gauge and a stout-link improved staggered
fermion action is utilized. We discuss partial quenching and present
preliminary results for the fully dynamical charmed equation of state.Comment: Talk presented at the XXIX International Symposium on Lattice Field
Theory, July 10-16, 2011, Lake Tahoe, Californi
N_f=2+1 flavour equation of state
We conclude our investigation on the QCD equation of state (EoS) with 2+1
staggered flavors and one-link stout improvement. We extend our previous study
[JHEP 0601:089 (2006)] by choosing even finer lattices. These new results [for
details see arXiv:1007.2580] support our earlier findings. Lattices with
N_t=6,8 and 10 are used, and the continuum limit is approached by checking the
results at N_t=12. A Symanzik improved gauge and a stout-link improved
staggered fermion action is taken; the light and strange quark masses are set
to their physical values. Various observables are calculated in the temperature
(T) interval of 100 to 1000~MeV. We compare our data to the equation of state
obtained by the "hotQCD" collaboration.Comment: presented at the XXVIII. International Symposium on Lattice Field
Theory, June 14-19,2010, Villasimius, Sardinia Ital
- …