Abstract
We present results from QCDOC for the dependence of the residual mass on the size of the fifth dimension, and its relation to the density and localisation properties of low eigenvectors of the Hermitian Wilson Dirac operator and the domain wall transfer matrix, for 2+1 flavour domain wall QCD using DBW2 and Iwasaki gauge actions. Using ensembles of 163 × 32 configurations, with an extent of 8 in the fifth dimension for the sea quarks, we demonstrate the existence of a regime where locality, chiral symmetry breaking and topology change can be acceptable for inverse lattice spacings a-1 > 1.6 GeV.
| Original language | English |
|---|---|
| Journal | Proceedings of Science |
| Volume | 20 |
| DOIs | |
| State | Published - 2005 |
| Externally published | Yes |
| Event | 23rd International Symposium on Lattice Field Theory, LAT 2005 - Dublin, Ireland Duration: Jul 25 2005 → Jul 30 2005 |
Funding
We thank Sam Li and Meifeng Lin for help generating the datasets used in this work. We thank Dong Chen, Norman Christ, Saul Cohen, Calin Cristian, Zhihua Dong, Alan Gara, Andrew Jackson, Chulwoo Jung, Changhoan Kim, Ludmila Levkova, Xiaodong Liao, Guofeng Liu, Robert Mawhinney, Shigemi Ohta, Konstantin Petrov and Tilo Wettig for developing with us the QCDOC machine and its software. This development and the resulting computer equipment used in this calculation were funded by the U.S.DOE grant DE-FG02-92ER40699, PPARC JIF grant PPA/J/S/1998/00756 and by RIKEN. This work was supported by PPARC grant PP/G/O/2002/00465 and we thank the University of Edinburgh for providing the facilities essential for the completion of this work. We find that for 3 flavour dynamical DWF simulations, at fixed lattice spacing, the DBW2 gauge action provides only marginal reduction in the residual mass compared with the Iwasaki gauge action. Residual chiral symmetry breaking of O(10−3) is achievable with both gauge actions in the region a−1 ≥ 1.6GeV for Ls ≥ 16. We demonstrate the connection between localised low eigenmodes of the transfer matrix, and a power-law contribution to mres. The presence of low modes creates an indefinite topological index of the chiral Dirac operator, such that both our results for ρ(0) and topological time histories [8] suggest that topology change survives at finer lattice spacings with the Iwasaki action outweighing the gain in residual mass from DBW2. 6. Acknowledgements We thank Sam Li and Meifeng Lin for help generating the datasets used in this work. We thank Dong Chen, Norman Christ, Saul Cohen, Calin Cristian, Zhihua Dong, Alan Gara, Andrew Jackson, Chulwoo Jung, Changhoan Kim, Ludmila Levkova, Xiaodong Liao, Guofeng Liu, Robert Mawhinney, Shigemi Ohta, Konstantin Petrov and Tilo Wettig for developing with us the QCDOC machine and its software. This development and the resulting computer equipment used in this calculation were funded by the U.S.DOE grant DE-FG02-92ER40699, PPARC JIF grant PPA/J/S/1998/00756 and by RIKEN. This work was supported by PPARC grant PP/G/O/2002/00465 and we thank the University of Edinburgh for providing the facilities essential for the completion of this work. References
| Funders | Funder number |
|---|---|
| PPARC | PPA/J/S/1998/00756 |
| U.S. Department of Energy | DE-FG02-92ER40699 |
| University of Edinburgh | |
| RIKEN | PP/G/O/2002/00465 |