arXiv:0911.0869·v1·High Energy Physics — Lattice
Progress on four flavor QCD with the HISQ action
MILC Collaboration: A. Bazavov (1) · C. Bernard (2) · C. DeTar (3) · W. Freeman (1) · Steven Gottlieb (4) · U.M. Heller (5) · J.E. Hetrick (6) · J. Laiho (2) · L. Levkova (3) · J. Osborn (7) · R. Sugar (8) · D. Toussaint (1) · R.S. Van de Water (9) · ((1) University of Arizona, (2) Washington University, (3) University of Utah, (4) Indiana University, (5) American Physical Society, (6) University of the Pacific, (7) Argonne National Laboratory, (8) University of California, Santa Barbara, (9) Brookhaven National Laboratory)
Abstract
We describe recent progress on generation of gauge configurations using the Highly Improved Staggered Quark (HISQ) action that was designed by the HPQCD/UKQCD collaboration. The HISQ action requires two levels of smearing with a reunitarization of the links before the second smearing. We describe how we deal with the occurrence of occasional large forces arising from the reunitarization step. The MILC collaboration is currently generating ensembles with approximate lattice spacings of 0.15, 0.12, 0.09, and 0.06 fm, with the strange and charm quark masses close to their physical values and the mass of the light quarks m_l set to 0.2 m_s. We present recent results for pion taste splittings, light hadron masses, the static potential, the eta_c dispersion relation and the topological susceptibility.
Comments: 8 pages, 7 figures, poster presented at The XXVII International Symposium on Lattice Field Theory - LAT2009, July 26-31 2009, Peking University, Beijing, China