Children learning to read: not quite so simple!

Copyright © 2001 Early Childhood Australia. Published version of the paper reproduced here with permission from the publisher

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

Freeze-out parameters from electric charge and baryon number fluctuations: is there consistency?

Recent results for moments of multiplicity distributions of net-protons and net-electric charge from the STAR collaboration are compared to lattice QCD results for higher order fluctuations of baryon number and electric charge by the Wuppertal-Budapest collaboration, with the purpose of extracting the freeze-out temperature and chemical potential. All lattice simulations are performed for a system of 2+1 dynamical quark flavors, at the physical mass for light and strange quarks; all results are continuum extrapolated. We show that it is possible to extract an upper value for the freeze-out temperature, as well as precise baryo-chemical potential values corresponding to the four highest collision energies of the experimental beam energy scan. Consistency between the freeze-out parameters obtained from baryon number and electric charge fluctuations is found. The freeze-out chemical potentials are now in agreement with the statistical hadronization model.Comment: 5 pages, 4 figures, references added, discussion added to the introduction, results unchange

Access, quality and equity in early childhood education and care: A South Australian study

Australian Journal of Education, 59/2, May/2015 published by SAGE Publishing, All rights reservedWhile much is known about the factors related to student performance beyond Grade 3 less is known about the factors that are related to student performance in early childhood education and the early years in primary school. As part of the 'I go to school' project in South Australia, this study tracked children attending integrated preschool/childcare centres -known as Children's Centres- as they made their transition to school. Results indicated that children who attended early childhood education programs that were of higher quality as characterised by higher staff qualifications and a greater range and more engaging children's activities showed a greater gain in cognitive development than children who attended lower quality programs. Findings also suggested that children who benefited the most from attendance in these programs were children from backgrounds of greater social disadvantage than children from less disadvantaged backgrounds

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 $N_f=2+1$ 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 $N_t=16$. 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

Freeze-out parameters: lattice meets experiment

We present our results for ratios of higher order fluctuations of electric charge as functions of the temperature. These results are obtained in a system of 2+1 quark flavors at physical quark masses and continuum extrapolated. We compare them to preliminary data on higher order moments of the net electric charge distribution from the STAR collaboration. This allows us to determine the freeze-out temperature and chemical potential from first principles. We also show continuum-extrapolated results for ratios of higher order fluctuations of baryon number. These will allow to test the consistency of the approach, by comparing them to the corresponding experimental data (once they become available) and thus extracting the freeze-out parameters in an independent way.Comment: 5 pages, 7 figures, revte

Chiral behavior of pseudo-Goldstone boson masses and decay constants in 2+1 flavor QCD

We present preliminary results for the chiral behavior of charged pseudo-Goldstone-boson masses and decay constants. These are obtained in simulations with N_f=2+1 flavors of tree-level, O(a)-improved Wilson sea quarks. In these simulations, mesons are composed of either valence quarks discretized in the same way as the sea quarks (unitary simulations) or of overlap valence quarks (mixed-action simulations). We find that the chiral behavior of the pseudoscalar meson masses in the mixed-action calculations cannot be explained with continuum, partially-quenched chiral perturbation theory. We show that the inclusion of O(a^2) unitarity violations in the chiral expansion resolves this discrepancy and that the size of the unitarity violations required are consistent with those which we observe in the zero-momentum, scalar-isotriplet-meson propagator.Comment: 7 pages, 3 figures, talk by L. Lellouch at the XXV International Symposium on Lattice Field Theory (LATTICE 2007), 30 July - 4 August 2007, Regensburg, German

QCD thermodynamics with dynamical overlap fermions

We study QCD thermodynamics using two flavors of dynamical overlap fermions with quark masses corresponding to a pion mass of 350 MeV. We determine several observables on N_t=6 and 8 lattices. All our runs are performed with fixed global topology. Our results are compared with staggered ones and a nice agreement is found.Comment: 14 pages, 6 figures, 1 tabl

Scaling study for 2 HEX smeared fermions: hadron and quark masses

The goal of this study is to investigate the scaling behaviour of our 2 HEX action. For this purpose, we compute the $N_f=3$ spectrum and compare the results to our 6 EXP action. We find a large scaling window up to $\sim 0.15\,\mathrm{fm}$ along with small scaling corrections at the 2%-level and full compatibility with our previous study. As a second important observable to be tested for scaling, we chose the non-perturbatively renormalized quenched strange quark mass. Here we find a fairly flat scaling with a broad scaling range up to $\simeq 0.15\,\mathrm{fm}$ and perfect agreement with the literature.Comment: PoS for the XXVIII International Symposium on Lattice Field Theory, Lattice2010, 7 pages, 4 figure