2,781 research outputs found
The ratio FK/Fpi in QCD
We determine the ratio FK/Fpi in QCD with Nf=2+1 flavors of sea quarks, based
on a series of lattice calculations with three different lattice spacings,
large volumes and a simulated pion mass reaching down to about 190 MeV. We
obtain FK/Fpi=1.192 +/- 0.007(stat) +/- 0.006(syst). This result is then used
to give an updated value of the CKM matrix element |Vus|. The unitarity
relation for the first row of this matrix is found to be well observed.Comment: 15 pages, 4 figures, 2 table
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
How do you spell bird? Effective parent programs to enhance 4-6 year old children's literacy development
This research examined the effectiveness of parent programs designed for families to support the literacy learning of their 4-6 year old children. The project began with a literature review analysing six established, effective parent programs that have been reported in the international and national research literature. An analysis of what made each of the programs effective entailed an analysis of the program's target population, the project inputs and activities and the initial, immediate and long term outcomes.
To explore further what local parents and families view as effective parent programs for 4-6 year old children the research explored individual site-specific parent programs in operation in South Australian childcare centres, preschools and schools in a range of diverse socioeconomic and geographic sites. Parents and teachers engaged in focus groups to describe ways the schools and centres sustain links between home and school learning.
To assess the elements of two existing parent programs to support children's early literacy development, parents and teachers participated in several focus groups. The two programs were the parent component of The Abecedarian Program (2001, 1979) developed in the United States and the South Australian Early Childhood Literacy Includes Parents Staff and Education ECLIPSE program (1997) developed by the South Australian Department of Education and Children's Services (DECS)
Precision computation of the kaon bag parameter
Indirect CP violation in K \rightarrow {\pi}{\pi} decays plays a central role
in constraining the flavor structure of the Standard Model (SM) and in the
search for new physics. For many years the leading uncertainty in the SM
prediction of this phenomenon was the one associated with the nonperturbative
strong interaction dynamics in this process. Here we present a fully controlled
lattice QCD calculation of these effects, which are described by the neutral
kaon mixing parameter B_K . We use a two step HEX smeared clover-improved
Wilson action, with four lattice spacings from a\approx0.054 fm to
a\approx0.093 fm and pion masses at and even below the physical value.
Nonperturbative renormalization is performed in the RI-MOM scheme, where we
find that operator mixing induced by chiral symmetry breaking is very small.
Using fully nonperturbative continuum running, we obtain our main result
B_K^{RI}(3.5GeV)=0.531(6)_{stat}(2)_{sys}. A perturbative 2-loop conversion
yields B_K^{MSbar-NDR}(2GeV)=0.564(6)_{stat}(3)_{sys}(6)_{PT}, which is in good
agreement with current results from fits to experimental data.Comment: 10 pages, 7 figures. v2: Added one reference and one figure, replaced
2 figures for better readability and updated ensembles, conclusions
unchanged. Final, published versio
Rho decay width from the lattice
While the masses of light hadrons have been extensively studied in lattice
QCD simulations, there exist only a few exploratory calculations of the strong
decay widths of hadronic resonances. We will present preliminary results of a
computation of the rho meson width obtained using flavor simulations.
The work is based on L\"uscher's formalism and its extension to moving frames.Comment: The XXVIII International Symposium on Lattice Field Theory, June
14-19,2010, Villasimius, Sardinia Ital
Electromagnetic corrections to light hadron masses
At the precision reached in current lattice QCD calculations, electromagnetic
effects are becoming numerically relevant. We will present preliminary results
for electromagnetic corrections to light hadron masses, based on simulations in
which a degree of freedom is superimposed on QCD
configurations from the BMW collaboration.Comment: 7 pages, 2 figures, The XXVIII International Symposium on Lattice
Field Theory, June 14-19,2010, Villasimius, Sardinia Ital
Field-Based Experience in Light of Changing Demographics
Due to changing demographics of students admitted to the School Psychology Training Program at Marshall University Graduate College, it has become imperative to significantly expand field experiences beginning in the first semester to address the lack of educational background of most of the students entering the program. This organized sequence of field experiences continues throughout the program, parallel to classroom instruction, affording opportunities for students to put theory into practice and to interact with professionals in the field, while also allowing for exposure to the public school environment. The collaborative field experience sequence provides the students with early and continuous feedback on their personal fit with schools as organizations and culminates with the summer enrichment program
In Vivo Predictive Dissolution: Comparing the Effect of Bicarbonate and Phosphate Buffer on the Dissolution of Weak Acids and Weak Bases
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113173/1/jps24460.pd
Hadronic vacuum polarization contribution to the anomalous magnetic moments of leptons from first principles
We compute the leading, strong-interaction contribution to the anomalous
magnetic moment of the electron, muon and tau using lattice quantum
chromodynamics (QCD) simulations. Calculations include the effects of , ,
and quarks and are performed directly at the physical values of the
quark masses and in volumes of linear extent larger than . All
connected and disconnected Wick contractions are calculated. Continuum limits
are carried out using six lattice spacings. We obtain
,
and
, where the first error
is statistical and the second is systematic.Comment: 17 pages, 8 figures (in 13 PDF files), RevTeX 4.1. Minor changes to
results and to text. References updated. Matches version published in
Physical Review Letter
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