The separation of a heavy quark and antiquark pair leads to the formation of a tube of flux, or string, which should break in the presence of light quarkantiquark pairs. This expected zero temperature phenomenon has proven elusive in simulations of lattice QCD. We present simulation results that show that the string does break in the confining phase at nonzero temperature. 11.15.Ha, 12.38.Gc, 1...

Given the increasing availability of lattice data for (unquenched) QCD with Nf = 2, it is worth while to check whether the generated vacuum significantly deviates from the quenched one. I discuss a specific attempt to do this on the basis of topological susceptibility data gained at various sea-quark masses, since for this observable detailed predictions are available. The upshot is that either...

We compute decay constants of heavy-light mesons in quenched lattice QCD with a lattice spacing of a ≃ 0.04 fm using non-perturbatively O(a) improved Wilson fermions and O(a) improved currents. We obtain fDs = 220(6)(5)(11) MeV, fD = 206(6)(3)(22) MeV, fBs = 205(7)(26)(17) MeV and fB = 190(8)(23)(25) MeV, using the Sommer parameter r0 = 0.5 fm to set the scale. The first error is statistical, t...

For many horticultural crops, selection is based on quality as well as yield. To investigate the distribution of trait variation and identify those attributes appropriate for developing selection indices, we collected and organized information related to fruit size, shape, color, soluble solids, acid, and yield traits for 143 processing tomato (Solanum lycopersicum L.) lines from North America....

The Dynamic, Exascale Global Address Space programming environment (DEGAS) project will develop the next generation of programming models and runtime systems to meet the challenges of Exascale computing. Our approach is to provide an efficient and scalable programming model that can be adapted to application needs through the use of dynamic runtime features and domain-specific languages for com...