QCD with Three Flavors of Improved Staggered Quarks

The MILC Collaboration:

S. Basak, A. Bazavov, C. Bernard, T. Burch, C. DeTar,

S. Gottlieb, U.M. Heller, J. Hetrick, J. Laiho, L. Levkova,

J. Osborn, R. Sugar, D. Toussaint

The MILC Collaboration is using the QCDOC, NERSC, the Pittsburgh Supercomputing Center and the KAON cluster at Fermilab to generate gauge configurations with three flavors of improved staggered quarks.  We plan to use these configurations to extend our studies of the hadron mass spectrum, the properties of light pseudoscalar mesons, the topological susceptibility, and, in collaboration with the Fermilab Lattice Collaboration, the decay properties of B and D mesons.  The configurations are available to members of the USQCD Collaboration as they are generated.  A number of other members of the Collaboration are using MILC configurations in their research, and others have indicated their intention to do so.

a(fm)
 ml/ms
 Lattice size
 Total Time
2007-8
 4/1/08
0.06
 0.3
 483 × 144
 3,500
 1,750
 1200
0.06
 0.1
 643 × 144 4,500
 2,800
 4,500
0.09
 0.3
 283 × 96 3,000
 3,000
 5,585
0.09
 0.15
 323 × 96 3,000
 3,000
 2,240
0.09
 0.2/0.6
 283 × 96 3,000
 3,000
 4,845
0.09
 0.1/0.6
 403 × 96 3,000
 3,000
 3,000

The fourth column of the table indicates the total number of equilibrated time units we proposed to generate at each lattice spacing and quark mass, the fifth column the number we expect to generate by July 1, 2008, and the sixth column the number generated as of 4/1/08.  For the last two ensembles the strange quark mass has been reduced from its physical value by 40 percent to get closer to the chiral limit and improve our determination of the constants in the chiral effective Lagrangian.