Unquenched QCD with Light Quarks

Abstract

We present recent results in unquenched lattice QCD with two degenerate light sea quarks using the truncated determinant approximation (TDA). In the TDA the infrared modes contributing to the quark determinant are computed exactly up to some cutoff in quark off-shellness (typically 2${\Lambda }_{QCD}$). This approach allows simulations to be performed at much lighter quark masses than possible with conventional hybrid MonteCarlo techniques. Results for the static energy and topological charge distributions are presented using a large ensemble generated on very coarse (6${}^4$) but physically large lattices. Preliminary results are also reported for the static energy and meson spectrum on 10${}^3$x20 lattices (lattice scale $a^{-1}$=1.15 GeV) at quark masses corresponding to pions of mass $\le$ 200 MeV. Using multiboson simulation to compute the ultraviolet part of the quark determinant the TDA approach becomes an exact with essentially no increase in computational effort. Some preliminary results using this fully unquenched algorithm are presented.

LateX, 39 pages, 16 eps figures, 1 ps figure

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Cited by in corpus (4)

• Lattice QCD at the end of 2003
• Fluctuations and reweighting of the quark determinant on large lattices
• Local Simulation Algorithms for Coulomb Gases with Dynamical Dielectric Effects
• Static potential and local color fields in unquenched lattice QCD${}_3$