Claude Bernard
(Washington University)
15/06/2010, 10:30
Chiral symmetry
We present results from the MILC collaboration's analysis of the light pseudoscalar
meson sector. All of our asqtad staggered ensembles with 2+1 dynamical quark flavors
have now been completed and analyzed, including lattice spacings down to 0.045 fm, and
light quark masses down to 0.05 times the strange mass. We compare the results
from SU(3) and SU(2) chiral perturbation theory; both...
Sebastien Descotes-Genon
(LPT (CNRS/Univ. Paris-Sud 11))
15/06/2010, 10:50
Chiral symmetry
Several lattice collaboration performing simulations with 2+1 light dynamical quarks have experienced difficulties in fitting their data with conventional NNLO expressions from N_f=3 Chiral Perturbation Theory, even for quantities as simple as pseudoscalar masses and decay constants. At the same time, they have obtained rather small values of the quark condensate and/or the decay constant in...
Jorge Martin Camalich
(IFIC-Valencia)
15/06/2010, 11:10
Chiral symmetry
We present an analysis of the baryon-octet and -decuplet masses using covariant SU(3)-flavor chiral perturbation theory up to next-to-leading order. Besides the description of the physical masses we address the problem of the lattice QCD extrapolation. More precisely, we study the $N_f=2+1$ results recently provided by the PACS-CS, LHPC and HSC collaborations. We show that a good description...
Fu-Jiun Jiang
(CTP, MIT)
15/06/2010, 11:30
Chiral symmetry
Using two-flavor chiral perturbation theories for hyperons, we study the
chiral corrections to the axial charges as well as the electromagnetic
properties of spin-1/2 hyperons. We first demonstrate that the virtual kaon
loop contributions are well described in the two-flavor theories by terms
analytic in the pion mass squared. We further show for the case of
experimentally known hyperon...
Elizabeth Freeland
(Washington University in St. Louis)
15/06/2010, 11:50
Chiral symmetry
To reduce errors in light-quark mass determinations from the lattice, it is now necessary to consider electromagnetic contributions to light-meson masses. Calculations with quenched photons are currently underway, and suitably-extended chiral perturbation theory is necessary to extrapolate the lattice data to the physical limit. We discuss issues of including electromagnetism on the lattice...
Tung-Han Hsieh
(Research Center for Applied Sciences, Academia Sinica)
15/06/2010, 12:10
Chiral symmetry
We determine the topological charge and its fluctuations for the gauge configurations generated by lattice simulations of 2 flavors QCD with optimal domain-wall fermion, on a $ 16^3 \times 32 \times 16 $ lattice with Wilson gauge action at $ \beta = 5.90 $. We project the low-lying modes of the lattice Dirac operator with the Lanczos thick-restart algorithm, and obtain the topological charge,...
