Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

High-Precision Lattice QCD Confronts Experiment

C. T. H. Davies, E. Follana, A. Gray, G. P. Lepage, Q. Mason, M. Nobes, J. Shigemitsu, H. D. Trottier, M. Wingate, C. Aubin, C. Bernard, T. Burch, C. DeTar, Steven Gottlieb, E. B. Gregory, U. M. Heller, J. E. Hetrick, J. Osborn, R. Sugar, D. Toussaint, M. Di Pierro, A. El-Khadra, A. S. Kronfeld, P. B. Mackenzie, D. Menscher, J. Simone

Abstract

We argue that high-precision lattice QCD is now possible, for the first time, because of a new improved staggered quark discretization. We compare a wide variety of nonperturbative calculations in QCD with experiment, and find agreement to within statistical and systematic errors of 3% or less. We also present a new determination of alpha_msbar(Mz); we obtain 0.121(3). We discuss the implications of this breakthrough for phenomenology and, in particular, for heavy-quark physics.

High-Precision Lattice QCD Confronts Experiment

Abstract

We argue that high-precision lattice QCD is now possible, for the first time, because of a new improved staggered quark discretization. We compare a wide variety of nonperturbative calculations in QCD with experiment, and find agreement to within statistical and systematic errors of 3% or less. We also present a new determination of alpha_msbar(Mz); we obtain 0.121(3). We discuss the implications of this breakthrough for phenomenology and, in particular, for heavy-quark physics.

Paper Structure

This paper contains 2 equations, 3 figures, 1 table.

Figures (3)

  • Figure 1: LQCD results divided by experimental results for nine different quantities, without and with quark vacuum polarization (left and right panels, respectively). The top three results are from our $a=1/11$ and $1/8$ fm simulations; all others are from $a=1/8$ fm simulations.
  • Figure 2: Chiral fits to LQCD determinations of $f_\pi$ and $f_K$ (in GeV) for different values of the valence $u/d$-quark mass at $a=1/11$ fm.
  • Figure 3: Gold-plated LQCD processes that bear on CKM matrix elements. $\epsilon_K$ is another gold-plated quantity.