HEP Lattice·hep-lat
6 papers—5 primary·1 cross-listed·reconstructed*
N. Cundy🇩🇪 · S. Krieg🇩🇪 · Th. Lippert🇩🇪
We present algorithmic improvements to the overlap Hybrid Monte Carlo algorithm, including preconditioning techniques and improvements to the correction step, used when one of the eigenvalues of the Kernel operator changes sign, which is now O(\Delta t^2) exact.
Sadataka Furui🇯🇵 · Hideo Nakajima🇯🇵
Quark propagators of the unquenched Kogut-Susskind(KS) fermion obtained from the gauge configurations of the MILC collaboration are measured after Landau gauge fixing and using the Staple+Naik action. Presence of the condensates and condensates in the dynamical mass and the quark wave function renormalization are investigated. We obtain the correlation of the renormalization factor of the running coupling taken at GeV and that of the quark wave function renormalization of the Staple+Naik action. The mass function is finite at and its chiral limit is GeV. We compared the results corrected by the scale of the vertex renormalization and the tadpole renormalization with the corresponding values obtained by the Asqtad action without renormalization and observed good agreement.Implication of infrared finite to the Kugo-Ojima confinement criterion is discussed.
Stephan Durr🇨🇭 · Christian Hoelbling🇩🇪 · Urs Wenger🇨🇭
Some key features of the overlap operator with a UV-filtered Wilson kernel are discussed. The first part concerns spectral properties of the underlying shifted hermitean Wilson operator and the relation to the observed speedup of the overlap construction. Next, the localization of the filtered overlap and its axial-vector renormalization constant are discussed. Finally, results of an exploratory scaling study for and are presented.
We discuss the adaptation of the Hybrid Monte Carlo algorithm to overlap fermions. We derive a method which can be used to account for the delta function in the fermionic force caused by the differential of the sign function. We discuss the algoritmic difficulties that have been overcome, and mention those that still need to be solved.
Eric B. Gregory🇬🇧 · Alan C. Irving🇬🇧 · Craig McNeile🇬🇧 · Steven Miller🇬🇧 · Zbyszek Sroczynski🇬🇧
We look for the effect of open decay channels on the masses of baryons in unquenched lattice QCD. We apply variational smearing using fuzzed basis states to a staggered nucleon operator. The signal for the s_bar s current in the nucleon is studied. The lattice calculations are done using improved staggered fermions.
Vladimir Pascalutsa🇺🇸 · Marc Vanderhaeghen (William-Mary College/JLab)🇺🇸
We study the chiral behavior of the nucleon and -isobar masses within a manifestly covariant chiral effective-field theory, consistent with the analyticity principle. We compute the and one-loop contributions to the mass and field-renormalization constant, and find that they can be described in terms of universal relativistic loop functions, multiplied by appropriate spin, isospin and coupling constants. We show that these relativistic one-loop corrections, when properly renormalized, obey the chiral power-counting and vanish in the chiral limit. The results including only the -loop corrections compare favorably with the lattice QCD data for the pion-mass dependence of the nucleon and masses, while inclusion of the loops tends to spoil this agreement.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.