Lattice QCD Summary Plots
Provided for reference are the most up-to-date (as of March 2010) versions of
several figures illustrating the contributions of lattice QCD. Click on the
figures to get a pdf version.
Gold-Plated Meson Spectrum
The masses of a number of "gold-plated" mesons
computed on the lattice and shown with their experimentally
determined values. This figure was published in
"Prediction of the Bc* Mass in Full Lattice QCD",
Phys. Rev. Lett. 104, 022001 (2010).
Ratio Plot
The ratio of fifteen "gold-plated" hadronic quantities --- masses, splittings
and decay constants --- computed on the lattice to their experimentally
determined values. The plot to the left is the ratio with the lattice values
coming from the "quenched approximation" with sea quark loops neglected, the
standard a decade ago. The right-hand plot reflects state-of-the-art
lattice calculations with full QCD, including light and strange quark loops.
Quark Masses
The masses of five flavors of quarks as determined by lattice QCD compared
to the values given by the
Particle Data Group.
The history of the strange quark mass.
Strong coupling constant
The value of αs determined by various methods. Lattice methods employ
non-perturbative determination of gluon loops coupled with higher-order
lattice QCD perturbation theory with energy scale determinations from the
Upsilon spectrum. Other methods employ continuum perturbation theory.
The lattice wloops calculation was published in
"Update: Accurate Determinations of αs from Realistic Lattice QCD",
Phys. Rev. D 78, 114507 (2008).
CKM matrix elements
Lattice QCD can determine the hadronic effects on quarks
involved in weak
interactions. By dividing these strong interaction effects out of
the experimentally measured weak interaction rates we can determine
the magnitude of the weak interaction, as expressed in the CKM matrix
elements.
