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In this talk, we shall assess the finite ma errors from the overlap fermion. We conclude from this study that one should be limited to using ma less than 0. Submitted 16 October, ; robot gas alarm rb-668 announced October The charmed-strange meson masses are calculated on a quenched lattice QCD.
The charm and strange quark propagators are calculated on the same lattice with the overlap fermion. The charmed strange meson spectrum for the scalar, axial, robot gas alarm rb-668 and vector channels are calculated.
They agree with experiments. Submitted 4 November, ; v1 submitted 16 October, ; originally announced October The charmed-strange meson spectrum from overlap fermions on domain wall dynamical fermion configurations. Both charm and strange quark propagators are calculated with the overlap fermion action. Submitted 2 December, ; v1 submitted 4 November, ; originally announced November As a physical test of the algorithm, we show that the forward matrix elements of the vector and pseudoscalar currents for the disconnected insertions are indeed consistent with the known results of zero.
We tried the Wuppertal smeared source and found it to robot gas alarm rb-668 more noisy robot gas alarm rb-668 the point source. The strange quark condensate in the nucleon is large, i. Submitted 12 December, ; originally announced December We study the valence approximation in lattice QCD of hadrons where the cloud quarks and antiquarks are deleted by truncating the backward time propagation Z robot gas alarm rb-668 in the connected insertions.
Whereas, the sea quarks are eliminated via the robot gas alarm rb-668 approximation and in the disconnected insertions. It is shown that the ratios of isovector to isoscalar matrix elements in the robot gas alarm rb-668 reproduce the SU 6 quark model predictions in a lattice QCD calculation.
We also discuss how the hadron masses are affected. Submitted 28 November, ; originally announced November Talk presented at Int. Using the Euclidean path-integral formulation for the hadronic tensor, we show that the violation of the Gottfried sum rule does not come from the disconnected quark-loop insertion.
Rather, it comes from the connected quark line insertion involving quarks propagating in the backward time direction. We demonstrate this by studying sum rules in terms of the scalar and axial- vector matrix elements in lattice gauge calculations. The effects of eliminating backward time propagation are presented.
Submitted 21 June, ; originally announced June HorvathNilmani MathurJ. Based on Bayesian theorem an empirical Baye's method is discussed.
A programming chart for robot gas alarm rb-668 spectrum fitting is suggested. A weakly constrained way for getting priors to solve the chiral log data fitting singularity is tested. Submitted 30 August, ; v1 submitted 26 August, ; originally announced August Nilmani MathurShao-Jing Dong.
Using an unbiased subtraction along with the help of charge conjugation and hermiticity, we reduce the error by a factor of 2 with negligible overhead. Submitted robot gas alarm rb-668 November, ; v1 submitted 1 November, ; originally announced November Lattice Hadronic Matrix Elements4 pages 2 figs. Study of stochastic estimates of quark loops with unbiased subtraction. Stochastic noise estimator method is a powerful tool to calculate the disconnected insertion involving quark loops.
We study the variance reduction technique with unbiased subtraction. Unbiased subtraction method is performed by using hoping parameter expansion. We report on the variance reduction for the point-split vector current as a function of the number of subtraction terms and the number robot gas alarm rb-668 noise used.
Submitted 3 September, ; originally announced September Lattice matrixel3 pages. Comparison of Multi-quark Matrix Inversion Algorithms.
Submitted 7 November, ; originally announced November The smallest pion mass we reach is about MeV. The lattice size is about 4 times the Compton wavelength of the lowest mass pion. Submitted 30 October, ; originally announced October Lattice Hadronic Matrix Elements3pages, 5figures. Submitted 11 October, ; originally announced October Lattice spectrum3 pages, 4 figures uses rotate. These are then used in robot gas alarm rb-668 augmented-chi-square fits on separate data.
This better stabilizes fits to lattice QCD overlap-fermion data at very low quark mass where a priori values are not otherwise known. Submitted 11 September, ; originally announced September Lattice machine3 pages, 3 figures. Submitted 23 August, ; originally announced August Lattice robot gas alarm rb-6683 pages, 3 figures. In order to evaluate the disconnected insertion DIwe use the Z 4 stochastic method, along with unbiased subtraction from the hopping parameter expansion which reduces the off-diagonal noises in the stochastic method.
Furthermore, we find that using many nucleon sources for each configuration is effective in improving the signal. Submitted 14 October, ; originally announced October The disconnected insertions are evaluated using the Z 4 stochastic method, along with unbiased subtractions from the hopping parameter expansion.
In addition to increasing the number of Z 4 noises, we find that increasing the number of nucleon sources for each configuration improves the signal significantly.
This is consistent with experimental values, and has an order of magnitude smaller error. Disconnected insertions are evaluated using the Z 4 stochastic method, along with unbiased subtractions from the hopping parameter expansion.
Robot gas alarm rb-668 find that increasing the number of nucleon sources for each configuration improves the signal significantly. Preliminary results for the strangeness contribution to robot gas alarm rb-668 second moment of the parton distribution function are also presented.
We evaluate disconnected insertions using the Z 4 stochastic method, along with unbiased subtractions from the hopping parameter expansion. Submitted 21 October, ; v1 submitted 18 March, ; originally announced March The overlap fermion offers the tremendous advantage of exact chiral symmetry on the lattice, but is numerically intensive. This can be made affordable while still providing large lattice volumes, by using coarse lattice spacing, given that good scaling and localization properties are established.
Here, using overlap fermions on quenched Iwasaki gauge configurations, we demonstrate directly that the overlap Dirac operator's range is comfortably robot gas alarm rb-668 in lattice robot gas alarm rb-668 for each of the lattice spacings 0.
Furthermore, hadronic masses available on the two coarser lattices scale very well. Submitted 13 October, ; originally announced October Lattice chiral fermions6 pages, 4 figures.
Non-perturbative renormalization of overlap quark bilinears on domain wall fermion configurations. Both overlap and domain wall fermions have chiral symmetry on the lattice. The scale independent renormalization constant for the local axial vector current is computed using a Ward Identity. The renormalization constants for the scalar, pseudoscalar and vector current are calculated in the RI-MOM scheme. Results in the MS-bar scheme are obtained by using perturbative conversion ratios.
Submitted 2 December, ; originally announced December Furthermore, we observe that the mass difference of the vector meson and the pseudoscalar meson with the same valence quark content is proportional to the reciprocal of the square root of the valence quark masses.
Submitted 30 July, ; v1 submitted robot gas alarm rb-668 October, ; originally announced October D 92, This setup is being used by the chiQCD collaboration in calculations of physical quantities such as strangeness in the nucleon robot gas alarm rb-668 the strange and charm quark masses. The scale independent renormalization constant for the axial vector current is computed using the Ward Identity. The renormalization constants for scalar, pseudoscalar and vector current are calculated in the RI-MOM scheme.
Results in the MS-bar scheme are also given. Submitted 19 August, ; v1 submitted 30 December, ; originally announced December A subsection for the calculation of the step scaling function of quark mass is added. Version to appear robot gas alarm rb-668 PRD. D 90, ThackerSonali TamhankarJianbo Zhang.
It is popular to probe the structure of the QCD vacuum indirectly by studying individual fermion eigenmodes, because this provides a natural way to filter out UV fluctuations. The double-peaking in the distribution of the local chiral orientation parameter X has been offered as evidence, by some, in support of a particular model of the vacuum.
Here we caution that the X-distribution robot gas alarm rb-668 varies significantly with various versions of the definition of X. Furthermore, each distribution varies little from that resulting from a random reshuffling of the left-handed and independently the right-handed fields, which destroys any QCD-induced left-right correlation; that is, the double-peaking is mostly a phase-space effect. We robot gas alarm rb-668 a new universal definition of the X parameter whose distribution is uniform for randomly reshuffled fields.
Any deviations from uniformity for actual data can then be directly attributable to QCD-induced dynamics. We find that the familiar double peak disappears. Submitted 4 August, ; originally announced August
